Bump mypy from 0.920 to 0.930

Bumps [mypy](https://github.com/python/mypy) from 0.920 to 0.930.
- [Release notes](https://github.com/python/mypy/releases)
- [Commits](https://github.com/python/mypy/compare/v0.920...v0.930)

---
updated-dependencies:
- dependency-name: mypy
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

requirements-dev.txt

@@ -6,7 +6,7 @@
 coveralls==3.3.1
 flake8==4.0.1
 flake8-tidy-imports==4.5.0
-mypy==0.920
+mypy==0.930
 pytest==6.2.5
 pytest-asyncio==0.16.0
 pytest-cov==3.0.0