Bump sphinx-autobuild from 0.7.1 to 2020.9.1

Bumps [sphinx-autobuild](https://github.com/GaretJax/sphinx_autobuild) from 0.7.1 to 2020.9.1.
- [Release notes](https://github.com/GaretJax/sphinx_autobuild/releases)
- [Commits](https://github.com/GaretJax/sphinx_autobuild/commits)

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

Author: dependabot[bot]

poetry.lock

@@ -45,7 +45,7 @@ pytest-django = "^3.9.0"
 pygments = "^2.6.1"
 xdoctest = "^0.14.0"
 sphinx = "^3.2.1"
-sphinx-autobuild = "^0.7.1"
+sphinx-autobuild = "^2020.9.1"
 darglint = "^1.5.3"
 flake8-docstrings = "^1.5.0"
 flake8-rst-docstrings = "^0.0.13"