Merge #14

14: Update sphinx_rtd_theme to 0.5.1 r=aragilar a=pyup-bot


This PR updates [sphinx_rtd_theme](https://pypi.org/project/sphinx_rtd_theme) from **0.5.0** to **0.5.1**.



*The bot wasn't able to find a changelog for this release. [Got an idea?](https://github.com/pyupio/changelogs/issues/new)*

<details>
  <summary>Links</summary>
  
  - PyPI: https://pypi.org/project/sphinx-rtd-theme
  - Repo: https://github.com/readthedocs/sphinx_rtd_theme
</details>



Co-authored-by: pyup-bot <[email protected]>

Author: bors[bot]

doc-requirements.txt

@@ -1,4 +1,4 @@
 sphinx>=1.3
 sphinxcontrib-napoleon>=0.4.3
 mock==3.0.5
-sphinx_rtd_theme==0.5.0
+sphinx_rtd_theme==0.5.1