diff --git a/.travis.yml b/.travis.yml
index a7630ca91..681d3dd76 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -34,10 +34,10 @@ before_install:
   hash -r &&
   conda config --set always_yes yes --set changeps1 no &&
   conda update -q conda &&
-  conda install python=${TRAVIS_PYTHON_VERSION} &&
   conda config --add channels conda-forge &&
-  conda install -y nipype icu &&
-  rm -r ${CONDA_HOME}/lib/python${TRAVIS_PYTHON_VERSION}/site-packages/nipype*;
+  conda install python=${TRAVIS_PYTHON_VERSION} &&
+  conda install -y icu &&
+  pip install -r requirements.txt &&
   pushd $HOME;
   git clone https://github.com/INCF/pybids.git;
   cd pybids;
diff --git a/nipype/interfaces/afni/__init__.py b/nipype/interfaces/afni/__init__.py
index bebcdab4b..6a1e7df76 100644
--- a/nipype/interfaces/afni/__init__.py
+++ b/nipype/interfaces/afni/__init__.py
@@ -22,7 +22,7 @@ from .svm import (SVMTest, SVMTrain)
 from .utils import (ABoverlap, AFNItoNIFTI, Autobox, Axialize, BrickStat,
                     Bucket, Calc, Cat, CatMatvec, CenterMass, Copy, Dot,
                     Edge3, Eval, FWHMx, MaskTool, Merge, Notes, NwarpApply,
-                    OneDToolPy,
+                    NwarpCat, OneDToolPy,
                     Refit, Resample, TCat, TCatSubBrick, TStat, To3D, Unifize,
                     Undump, ZCutUp, GCOR,
                     Zcat, Zeropad)
diff --git a/nipype/interfaces/afni/utils.py b/nipype/interfaces/afni/utils.py
index f7281542a..824557878 100644
--- a/nipype/interfaces/afni/utils.py
+++ b/nipype/interfaces/afni/utils.py
@@ -1588,6 +1588,123 @@ class NwarpApply(AFNICommandBase):
     input_spec = NwarpApplyInputSpec
     output_spec = AFNICommandOutputSpec
 
+
+class NwarpCatInputSpec(AFNICommandInputSpec):
+    in_files = traits.List(
+        traits.Either(
+            traits.File(),
+            traits.Tuple(traits.Enum('IDENT', 'INV', 'SQRT', 'SQRTINV'),
+                         traits.File())),
+        descr="list of tuples of 3D warps and associated functions",
+        mandatory=True,
+        argstr="%s",
+        position=-1)
+    space = traits.String(
+        desc='string to attach to the output dataset as its atlas space '
+             'marker.',
+        argstr='-space %s')
+    inv_warp = traits.Bool(
+        desc='invert the final warp before output',
+        argstr='-iwarp')
+    interp = traits.Enum(
+        'linear', 'quintic', 'wsinc5',
+        desc='specify a different interpolation method than might '
+             'be used for the warp',
+        argstr='-interp %s',
+        default='wsinc5')
+    expad = traits.Int(
+        desc='Pad the nonlinear warps by the given number of voxels voxels in '
+             'all directions. The warp displacements are extended by linear '
+             'extrapolation from the faces of the input grid..',
+        argstr='-expad %d')
+    out_file = File(
+        name_template='%s_NwarpCat',
+        desc='output image file name',
+        argstr='-prefix %s',
+        name_source='in_files')
+    verb = traits.Bool(
+        desc='be verbose',
+        argstr='-verb')
+
+
+class NwarpCat(AFNICommand):
+    """Catenates (composes) 3D warps defined on a grid, OR via a matrix.
+
+    .. note::
+
+      * All transformations are from DICOM xyz (in mm) to DICOM xyz.
+
+      * Matrix warps are in files that end in '.1D' or in '.txt'.  A matrix
+        warp file should have 12 numbers in it, as output (for example), by
+        '3dAllineate -1Dmatrix_save'.
+
+      * Nonlinear warps are in dataset files (AFNI .HEAD/.BRIK or NIfTI .nii)
+        with 3 sub-bricks giving the DICOM order xyz grid displacements in mm.
+
+      * If all the input warps are matrices, then the output is a matrix
+        and will be written to the file 'prefix.aff12.1D'.
+        Unless the prefix already contains the string '.1D', in which case
+        the filename is just the prefix.
+
+      * If 'prefix' is just 'stdout', then the output matrix is written
+        to standard output.
+        In any of these cases, the output format is 12 numbers in one row.
+
+      * If any of the input warps are datasets, they must all be defined on
+        the same 3D grid!
+        And of course, then the output will be a dataset on the same grid.
+        However, you can expand the grid using the '-expad' option.
+
+      * The order of operations in the final (output) warp is, for the
+        case of 3 input warps:
+
+            OUTPUT(x) = warp3( warp2( warp1(x) ) )
+
+       That is, warp1 is applied first, then warp2, et cetera.
+       The 3D x coordinates are taken from each grid location in the
+       first dataset defined on a grid.
+
+    For complete details, see the `3dNwarpCat Documentation.
+    <https://afni.nimh.nih.gov/pub/dist/doc/program_help/3dNwarpCat.html>`_
+
+    Examples
+    ========
+
+    >>> from nipype.interfaces import afni
+    >>> nwarpcat = afni.NwarpCat()
+    >>> nwarpcat.inputs.in_files = ['Q25_warp+tlrc.HEAD', ('IDENT', 'structural.nii')]
+    >>> nwarpcat.inputs.out_file = 'Fred_total_WARP'
+    >>> nwarpcat.cmdline  # doctest: +ALLOW_UNICODE
+    "3dNwarpCat -prefix Fred_total_WARP Q25_warp+tlrc.HEAD 'IDENT(structural.nii)'"
+    >>> res = nwarpcat.run()  # doctest: +SKIP
+
+    """
+    _cmd = '3dNwarpCat'
+    input_spec = NwarpCatInputSpec
+    output_spec = AFNICommandOutputSpec
+
+    def _format_arg(self, name, spec, value):
+        if name == 'in_files':
+            return spec.argstr % (' '.join(["'" + v[0] + "(" + v[1] + ")'"
+                                            if isinstance(v, tuple) else v
+                                            for v in value]))
+        return super(NwarpCat, self)._format_arg(name, spec, value)
+
+    def _gen_filename(self, name):
+        if name == 'out_file':
+            return self._gen_fname(self.inputs.in_files[0][0],
+                                   suffix='_NwarpCat')
+
+    def _list_outputs(self):
+        outputs = self.output_spec().get()
+        if isdefined(self.inputs.out_file):
+            outputs['out_file'] = os.path.abspath(self.inputs.out_file)
+        else:
+            outputs['out_file'] = os.path.abspath(self._gen_fname(
+                self.inputs.in_files[0], suffix='_NwarpCat+tlrc', ext='.HEAD'))
+        return outputs
+
+
 class OneDToolPyInputSpec(AFNIPythonCommandInputSpec):
     in_file = File(
         desc='input file to OneDTool',
diff --git a/nipype/interfaces/bids_utils.py b/nipype/interfaces/bids_utils.py
index 0bbc89509..0259a8035 100644
--- a/nipype/interfaces/bids_utils.py
+++ b/nipype/interfaces/bids_utils.py
@@ -6,15 +6,15 @@ available interfaces are:
 
 BIDSDataGrabber: Query data from BIDS dataset using pybids grabbids.
 
-Change directory to provide relative paths for doctests
->>> import os
->>> import bids
->>> filepath = os.path.realpath(os.path.dirname(bids.__file__))
->>> datadir = os.path.realpath(os.path.join(filepath, 'grabbids/tests/data/'))
->>> os.chdir(datadir)
 
+    Change directory to provide relative paths for doctests
+    >>> import os
+    >>> filepath = os.path.dirname( os.path.realpath( __file__ ) )
+    >>> datadir = os.path.realpath(os.path.join(filepath, '../testing/data'))
+    >>> os.chdir(datadir)
 """
 from os.path import join, dirname
+import json
 from .. import logging
 from .base import (traits,
                    DynamicTraitedSpec,
@@ -24,13 +24,11 @@ from .base import (traits,
                    Str,
                    Undefined)
 
+have_pybids = True
 try:
     from bids import grabbids as gb
-    import json
 except ImportError:
     have_pybids = False
-else:
-    have_pybids = True
 
 LOGGER = logging.getLogger('workflows')
 
@@ -56,9 +54,6 @@ class BIDSDataGrabber(BaseInterface):
     Examples
     --------
 
-    >>> from nipype.interfaces.bids_utils import BIDSDataGrabber
-    >>> from os.path import basename
-
     By default, the BIDSDataGrabber fetches anatomical and functional images
     from a project, and makes BIDS entities (e.g. subject) available for
     filtering outputs.
@@ -66,12 +61,7 @@ class BIDSDataGrabber(BaseInterface):
     >>> bg = BIDSDataGrabber()
     >>> bg.inputs.base_dir = 'ds005/'
     >>> bg.inputs.subject = '01'
-    >>> results = bg.run()
-    >>> basename(results.outputs.anat[0]) # doctest: +ALLOW_UNICODE
-    'sub-01_T1w.nii.gz'
-
-    >>> basename(results.outputs.func[0]) # doctest: +ALLOW_UNICODE
-    'sub-01_task-mixedgamblestask_run-01_bold.nii.gz'
+    >>> results = bg.run() # doctest: +SKIP
 
 
     Dynamically created, user-defined output fields can also be defined to
@@ -83,9 +73,7 @@ class BIDSDataGrabber(BaseInterface):
     >>> bg.inputs.base_dir = 'ds005/'
     >>> bg.inputs.subject = '01'
     >>> bg.inputs.output_query['dwi'] = dict(modality='dwi')
-    >>> results = bg.run()
-    >>> basename(results.outputs.dwi[0]) # doctest: +ALLOW_UNICODE
-    'sub-01_dwi.nii.gz'
+    >>> results = bg.run() # doctest: +SKIP
 
     """
     input_spec = BIDSDataGrabberInputSpec
@@ -104,32 +92,32 @@ class BIDSDataGrabber(BaseInterface):
             If no matching items, returns Undefined.
         """
         super(BIDSDataGrabber, self).__init__(**kwargs)
-        if not have_pybids:
-            raise ImportError(
-                "The BIDSEventsGrabber interface requires pybids."
-                " Please make sure it is installed.")
 
         if not isdefined(self.inputs.output_query):
             self.inputs.output_query = {"func": {"modality": "func"},
                                         "anat": {"modality": "anat"}}
 
-        # If infields is None, use all BIDS entities
-        if infields is None:
+        # If infields is empty, use all BIDS entities
+        if not infields is None and have_pybids:
             bids_config = join(dirname(gb.__file__), 'config', 'bids.json')
             bids_config = json.load(open(bids_config, 'r'))
             infields = [i['name'] for i in bids_config['entities']]
 
-        self._infields = infields
+        self._infields = infields or []
 
         # used for mandatory inputs check
         undefined_traits = {}
-        for key in infields:
+        for key in self._infields:
             self.inputs.add_trait(key, traits.Any)
             undefined_traits[key] = kwargs[key] if key in kwargs else Undefined
 
         self.inputs.trait_set(trait_change_notify=False, **undefined_traits)
 
     def _run_interface(self, runtime):
+        if not have_pybids:
+            raise ImportError(
+                "The BIDSEventsGrabber interface requires pybids."
+                " Please make sure it is installed.")
         return runtime
 
     def _list_outputs(self):
diff --git a/nipype/interfaces/io.py b/nipype/interfaces/io.py
index f2e3fcd94..4d3220b04 100644
--- a/nipype/interfaces/io.py
+++ b/nipype/interfaces/io.py
@@ -1188,15 +1188,18 @@ class SelectFilesInputSpec(DynamicTraitedSpec, BaseInterfaceInputSpec):
     base_directory = Directory(exists=True,
                                desc="Root path common to templates.")
     sort_filelist = traits.Bool(True, usedefault=True,
-                                desc="When matching mutliple files, return them in sorted order.")
+                                desc="When matching mutliple files, return them"
+                                " in sorted order.")
     raise_on_empty = traits.Bool(True, usedefault=True,
-                                 desc="Raise an exception if a template pattern matches no files.")
+                                desc="Raise an exception if a template pattern "
+                                "matches no files.")
     force_lists = traits.Either(traits.Bool(), traits.List(Str()),
                                 default=False, usedefault=True,
-                                desc=("Whether to return outputs as a list even when only one file "
-                                      "matches the template. Either a boolean that applies to all "
-                                      "output fields or a list of output field names to coerce to "
-                                      " a list"))
+                                desc=("Whether to return outputs as a list even"
+                                " when only one file matches the template. "
+                                "Either a boolean that applies to all output "
+                                "fields or a list of output field names to "
+                                "coerce to a list"))
 
 
 class SelectFiles(IOBase):
@@ -1296,6 +1299,8 @@ class SelectFiles(IOBase):
 
         for field, template in list(self._templates.items()):
 
+            find_dirs = template[-1] == os.sep
+
             # Build the full template path
             if isdefined(self.inputs.base_directory):
                 template = op.abspath(op.join(
@@ -1303,6 +1308,10 @@ class SelectFiles(IOBase):
             else:
                 template = op.abspath(template)
 
+            # re-add separator if searching exclusively for directories
+            if find_dirs:
+                template += os.sep
+
             # Fill in the template and glob for files
             filled_template = template.format(**info)
             filelist = glob.glob(filled_template)
diff --git a/nipype/testing/data/ds005/filler.txt b/nipype/testing/data/ds005/filler.txt
new file mode 100644
index 000000000..e69de29bb
diff --git a/nipype/utils/filemanip.py b/nipype/utils/filemanip.py
index 72cb1fc15..e8a9ea22b 100644
--- a/nipype/utils/filemanip.py
+++ b/nipype/utils/filemanip.py
@@ -646,3 +646,20 @@ def write_rst_dict(info, prefix=''):
     for key, value in sorted(info.items()):
         out.append('{}* {} : {}'.format(prefix, key, str(value)))
     return '\n'.join(out) + '\n\n'
+
+
+def dist_is_editable(dist):
+    """Is distribution an editable install?
+
+    Parameters
+    ----------
+    dist : string
+        Package name
+
+    # Borrowed from `pip`'s' API
+    """
+    for path_item in sys.path:
+        egg_link = os.path.join(path_item, dist + '.egg-link')
+        if os.path.isfile(egg_link):
+            return True
+    return False

diff --git a/nipype/interfaces/afni/tests/test_auto_NwarpCat.py b/nipype/interfaces/afni/tests/test_auto_NwarpCat.py
new file mode 100644
index 000000000..6e5077e64
--- /dev/null
+++ b/nipype/interfaces/afni/tests/test_auto_NwarpCat.py
@@ -0,0 +1,56 @@
+# AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
+from ..utils import NwarpCat
+
+
+def test_NwarpCat_inputs():
+    input_map = dict(args=dict(argstr='%s',
+    ),
+    environ=dict(nohash=True,
+    usedefault=True,
+    ),
+    expad=dict(argstr='-expad %d',
+    ),
+    ignore_exception=dict(nohash=True,
+    usedefault=True,
+    ),
+    in_files=dict(argstr='%s',
+    descr='list of tuples of 3D warps and associated functions',
+    mandatory=True,
+    position=-1,
+    ),
+    interp=dict(argstr='-interp %s',
+    ),
+    inv_warp=dict(argstr='-iwarp',
+    ),
+    num_threads=dict(nohash=True,
+    usedefault=True,
+    ),
+    out_file=dict(argstr='-prefix %s',
+    name_source='in_files',
+    name_template='%s_NwarpCat',
+    ),
+    outputtype=dict(),
+    space=dict(argstr='-space %s',
+    ),
+    terminal_output=dict(deprecated='1.0.0',
+    nohash=True,
+    ),
+    verb=dict(argstr='-verb',
+    ),
+    )
+    inputs = NwarpCat.input_spec()
+
+    for key, metadata in list(input_map.items()):
+        for metakey, value in list(metadata.items()):
+            assert getattr(inputs.traits()[key], metakey) == value
+
+
+def test_NwarpCat_outputs():
+    output_map = dict(out_file=dict(),
+    )
+    outputs = NwarpCat.output_spec()
+
+    for key, metadata in list(output_map.items()):
+        for metakey, value in list(metadata.items()):
+            assert getattr(outputs.traits()[key], metakey) == value
diff --git a/nipype/interfaces/tests/test_bids.py b/nipype/interfaces/tests/test_bids.py
new file mode 100644
index 000000000..aa5bc6c35
--- /dev/null
+++ b/nipype/interfaces/tests/test_bids.py
@@ -0,0 +1,50 @@
+import os
+import json
+import sys
+
+import pytest
+from nipype.interfaces.bids_utils import BIDSDataGrabber
+from nipype.utils.filemanip import dist_is_editable
+
+have_pybids = True
+try:
+    import bids
+    from bids import grabbids as gb
+    filepath = os.path.realpath(os.path.dirname(bids.__file__))
+    datadir = os.path.realpath(os.path.join(filepath, 'grabbids/tests/data/'))
+except ImportError:
+    have_pybids = False
+
+
+# There are three reasons these tests will be skipped:
+@pytest.mark.skipif(not have_pybids,
+                    reason="Pybids is not installed")
+@pytest.mark.skipif(sys.version_info < (3, 0),
+                    reason="Pybids no longer supports Python 2")
+@pytest.mark.skipif(not dist_is_editable('pybids'),
+                    reason="Pybids is not installed in editable mode")
+def test_bids_grabber(tmpdir):
+    tmpdir.chdir()
+    bg = BIDSDataGrabber()
+    bg.inputs.base_dir = os.path.join(datadir, 'ds005')
+    bg.inputs.subject = '01'
+    results = bg.run()
+    assert os.path.basename(results.outputs.anat[0]) == 'sub-01_T1w.nii.gz'
+    assert os.path.basename(results.outputs.func[0]) == (
+           'sub-01_task-mixedgamblestask_run-01_bold.nii.gz')
+
+
+@pytest.mark.skipif(not have_pybids,
+                    reason="Pybids is not installed")
+@pytest.mark.skipif(sys.version_info < (3, 0),
+                    reason="Pybids no longer supports Python 2")
+@pytest.mark.skipif(not dist_is_editable('pybids'),
+                    reason="Pybids is not installed in editable mode")
+def test_bids_fields(tmpdir):
+    tmpdir.chdir()
+    bg = BIDSDataGrabber(infields = ['subject'], outfields = ['dwi'])
+    bg.inputs.base_dir = os.path.join(datadir, 'ds005')
+    bg.inputs.subject = '01'
+    bg.inputs.output_query['dwi'] = dict(modality='dwi')
+    results = bg.run()
+    assert os.path.basename(results.outputs.dwi[0]) == 'sub-01_dwi.nii.gz'
diff --git a/nipype/interfaces/tests/test_resource_monitor.py b/nipype/interfaces/tests/test_resource_monitor.py
index 660f11455..8374ba7ac 100644
--- a/nipype/interfaces/tests/test_resource_monitor.py
+++ b/nipype/interfaces/tests/test_resource_monitor.py
@@ -45,6 +45,7 @@ class UseResources(CommandLine):
     _always_run = True
 
 
+@pytest.mark.skip(reason="inconsistent readings")
 @pytest.mark.skipif(os.getenv('CI_SKIP_TEST', False), reason='disabled in CI tests')
 @pytest.mark.parametrize("mem_gb,n_procs", [(0.5, 3), (2.2, 8), (0.8, 4), (1.5, 1)])
 def test_cmdline_profiling(tmpdir, mem_gb, n_procs):

Testing the install:  "UNEXPECTED EXCEPTION: ImportError("No module named 'bids'",)"
### Summary
While testing the installation with `python -c "import nipype; nipype.test()" ` I got the following error
```
==================================================================================================================================== FAILURES =====================================================================================================================================
_____________________________________________________________________________________________________________________ [doctest] nipype.interfaces.bids_utils ______________________________________________________________________________________________________________________
UNEXPECTED EXCEPTION: ImportError("No module named 'bids'",)
Traceback (most recent call last):

  File "/home/athanell/anaconda3/envs/SAH/lib/python3.5/doctest.py", line 1321, in __run
    compileflags, 1), test.globs)

  File "<doctest nipype.interfaces.bids_utils[1]>", line 1, in <module>

ImportError: No module named 'bids'

/home/athanell/.local/lib/python3.5/site-packages/nipype/interfaces/bids_utils.py:11: UnexpectedException
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Interrupted: stopping after 1 failures !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
================================================================================================================ 1 failed, 143 passed, 5 skipped in 29.53 seconds =================================================================================================================
```
Is this something that will hinder the usage of nipype and should be fixed? If yes how should I go about it?

Thank you
 



### Platform details:

```
{'nibabel_version': '2.1.0', 'sys_executable': '/home/athanell/anaconda3/envs/SAH/bin/python', 'scipy_version': '0.19.1', 'networkx_version': '2.0', 'sys_platform': 'linux', 'pkg_path': '/home/athanell/.local/lib/python3.5/site-packages/nipype', 'commit_source': 'installation', 'nipype_version': '1.0.0-dev', 'numpy_version': '1.13.3', 'sys_version': '3.5.4 |Anaconda, Inc.| (default, Oct  5 2017, 08:00:22) \n[GCC 7.2.0]', 'commit_hash': 'e4e95f3', 'traits_version': '4.6.0'}
1.0.0-dev

```

nipype/interfaces/afni/tests/test_auto_NwarpCat.py::test_NwarpCat_inputs nipype/interfaces/afni/tests/test_auto_NwarpCat.py::test_NwarpCat_outputs