Merge #216

216: Update sphinx to 4.0.1 r=YourLocalBlake a=pyup-bot


This PR updates [sphinx](https://pypi.org/project/sphinx) from **4.0.0** to **4.0.1**.



<details>
  <summary>Changelog</summary>
  
  
   ### 4.0.1
   ```
   =====================================

Bugs fixed
----------

* 9189: autodoc: crashed when ValueError is raised on generating signature
  from a property of the class
* 9188: autosummary: warning is emitted if list value is set to
  autosummary_generate
* 8380: html search: tags for search result are broken
* 9198: i18n: Babel emits errors when running compile_catalog
* 9205: py domain: The :canonical: option causes &quot;more than one target for
  cross-reference&quot; warning
* 9201: websupport: UndefinedError is raised: &#39;css_tag&#39; is undefined
   ```
   
  
</details>


 

<details>
  <summary>Links</summary>
  
  - PyPI: https://pypi.org/project/sphinx
  - Changelog: https://pyup.io/changelogs/sphinx/
  - Homepage: http://sphinx-doc.org/
</details>



Co-authored-by: pyup-bot <github-bot@pyup.io>

doc-requirements.txt

@@ -1,3 +1,3 @@
 mock==4.0.3
 sphinx_rtd_theme==0.5.2
-sphinx==4.0.0
+sphinx==4.0.1