title: Sphinx "reference target not found" warning
body: <p>After creating a PR against the Django project Sphinx is emitting these warnings when running:</p>
  
  <pre><code>make html
  </code></pre>
  
  <p>locally:</p>
  
  <pre><code>/path-to-project-dir/django/docs/releases/1.10.txt:304: WARNING: py:meth reference target not found: django.test.testcases.SimpleTestCase.assertFormValid
  /path-to-project-dir/django/docs/releases/1.10.txt:304: WARNING: py:meth reference target not found: django.test.testcases.SimpleTestCase.assertFormNotValid
  </code></pre>
  
  <p>Basically Sphinx is reporting it's missing references.</p>
  
  <p>The error (actually a warning) also happens while building docs: <a href="http://djangoci.com/job/docs/7444/console" rel="nofollow noreferrer">http://djangoci.com/job/docs/7444/console</a>.</p>
  
  <p>Answers to a <a href="https://stackoverflow.com/q/10324393/1211429">question reporting a similar issue </a> suggest editing <code>docs/conf.py</code>; however in this case this is not an option as the effect would be to edit <code>docs/conf.py</code> for the whole Django project.</p>
  
  <p>Any solution to this issue that does not involve changing <code>docs/conf.py</code>?</p>