Bump sphinx from 3.0.2 to 3.0.3

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 3.0.2 to 3.0.3.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/3.x/CHANGES)
- [Commits](sphinx-doc/sphinx@v3.0.2...v3.0.3)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

requirements.txt

@@ -10,5 +10,5 @@ gunicorn==20.0.4
 pycodestyle==2.5.0
 pydocstyle==5.0.2
 requests==2.23.0
-Sphinx==3.0.2
+Sphinx==3.0.3
 Werkzeug==1.0.1