Error while deploying NodeJs app on Heroku
<p>I've tried to deploy my NodeJs app on Heroku, follows all steps on Heroku guide but I can't make it running. Here is the log:</p>

<pre><code>2016-06-27T18:46:16.424477+00:00 heroku[web.1]: State changed from crashed to starting
    2016-06-27T18:46:18.594534+00:00 heroku[web.1]: Starting process with command `npm start`
    2016-06-27T18:46:21.204182+00:00 app[web.1]: npm ERR! Linux 3.13.0-85-generic
    2016-06-27T18:46:21.205909+00:00 app[web.1]: npm ERR! npm  v3.8.6
    2016-06-27T18:46:21.204971+00:00 app[web.1]: npm ERR! argv "/app/.heroku/node/bin/node" "/app/.heroku/node/bin/npm" "start"
    2016-06-27T18:46:21.209309+00:00 app[web.1]: npm ERR! missing script: start
    2016-06-27T18:46:21.221679+00:00 app[web.1]: npm ERR! Please include the following file with any support request:
    2016-06-27T18:46:21.209934+00:00 app[web.1]: npm ERR!     &lt;https://github.com/npm/npm/issues&gt;
    2016-06-27T18:46:21.207755+00:00 app[web.1]: 
    2016-06-27T18:46:21.221362+00:00 app[web.1]: 
    2016-06-27T18:46:21.209552+00:00 app[web.1]: npm ERR! 
    2016-06-27T18:46:21.209740+00:00 app[web.1]: npm ERR! If you need help, you may report this error at:
    2016-06-27T18:46:21.221872+00:00 app[web.1]: npm ERR!     /app/npm-debug.log
    2016-06-27T18:46:21.205374+00:00 app[web.1]: npm ERR! node v5.11.1
    2016-06-27T18:46:22.240678+00:00 heroku[web.1]: Process exited with status 1
    2016-06-27T18:46:22.255389+00:00 heroku[web.1]: State changed from starting to crashed
</code></pre>

<p>Any thoughts?</p>

<p>[EDIT]</p>

<p>package.json: </p>

<pre><code>"engines": {
  "node": "5.11.1",
  "npm": "3.8.6"
  },
  "scripts": {
    "start": "node app.js"
  },
</code></pre>

<p>Procfile:</p>

<pre><code>web: npm start
</code></pre>