title: Failed to import module when building the sphinx documentation
body: <p>I'm using <code>Sphinx</code> version <code>1.4.5</code>.</p>
  
  <p>My project structure is the following:</p>
  
  <p><code>+ src &gt; main.py
  + docs (generated with sphinx-quickstart)</code></p>
  
  <p>Even after adding the path to the <code>src</code> folder in <code>docs/conf.py</code>:</p>
  
  <pre class="lang-py prettyprint-override"><code>sys.path.insert(0, os.path.abspath('../src'))
  </code></pre>
  
  <p>And generating the rst file for <code>src/main.py</code> (i.e. <code>docs/src.rst</code> and <code>docs/modules.rst</code>) with:</p>
  
  <pre class="lang-sh prettyprint-override"><code>$ sphinx-apidoc -fo docs src
  </code></pre>
  
  <p>When I try to build the <code>html</code> webpages with:</p>
  
  <pre class="lang-sh prettyprint-override"><code>$ make clean
  $ make html
  </code></pre>
  
  <p>It couldn't find both the <code>src</code> module and <code>src/main.py</code>:</p>
  
  <p><code>WARNING: autodoc: failed to import module u'src.main'; the following exception was raised</code></p>