Bump sphinx-autoapi from 1.5.1 to 1.6.0

Bumps [sphinx-autoapi](https://github.com/readthedocs/sphinx-autoapi) from 1.5.1 to 1.6.0.
- [Release notes](https://github.com/readthedocs/sphinx-autoapi/releases)
- [Changelog](https://github.com/readthedocs/sphinx-autoapi/blob/master/CHANGELOG.rst)
- [Commits](readthedocs/sphinx-autoapi@v1.5.1...v1.6.0)

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

Author: dependabot-preview[bot]

poetry.lock

@@ -29,7 +29,7 @@ pytest-cov = "^2.11.0"
 jsonschema = "^3.2.0"
 pylint = "^2.6.0"
 sphinx = "^3.4.3"
-sphinx-autoapi = "^1.4.0"
+sphinx-autoapi = "^1.6.0"
 sphinx-rtd-theme = "^0.5.1"
 mypy = "^0.790"