This was fixed in #1184
Travis CI ERROR: JAVA_HOME is set to an invalid directory
Travis CI builds started failing with "ERROR: JAVA_HOME is set to an invalid directory: /usr/lib/jvm/java-7-oracle". [Example failure](https://travis-ci.org/mockito/mockito/jobs/270842998).

```
$ ./gradlew build idea -s -PcheckJava6Compatibility && ./gradlew ciPerformRelease
ERROR: JAVA_HOME is set to an invalid directory: /usr/lib/jvm/java-7-oracle
Please set the JAVA_HOME variable in your environment to match the
location of your Java installation.
```

It looks like there was some incompatible change rolled out in Travis CI.
.travis.yml
.travis.yml
diff --git a/.travis.yml b/.travis.yml
index e626d42d1a..096880fcb6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -15,11 +15,7 @@ language: java
 
 matrix:
   include:
-  - jdk: oraclejdk7
-  - jdk: oraclejdk7
-    env: SKIP_RELEASE=true MOCK_MAKER=mock-maker-inline
   - jdk: oraclejdk8
-    env: SKIP_RELEASE=true
   - jdk: oraclejdk8
     env: SKIP_RELEASE=true MOCK_MAKER=mock-maker-inline
 
