title: Python build ignores yaml file although it is specified in Manifest.in
body: <p>I'm currently trying to create a package out of my project unfortunately a yaml file that contains some meta information is ignored.</p>
  <p>The file is in mypackage/resources/about.yaml</p>
  <p>Any ideas ?</p>
  <p>Here my MANIFEST.in</p>
  <pre><code>recursive-include mypackage *.py
  recursive-include mypackage *.pickle
  recursive-include mypackage *.yaml
  include mypackage/resources/about.yaml
  include README.md
  include requirements.txt
  include dependency_links.txt
  </code></pre>