Bump pytest-mypy from 0.4.2 to 0.5.0

Bumps [pytest-mypy](https://github.com/dbader/pytest-mypy) from 0.4.2 to 0.5.0.
- [Release notes](https://github.com/dbader/pytest-mypy/releases)
- [Changelog](https://github.com/dbader/pytest-mypy/blob/master/changelog.md)
- [Commits](realpython/pytest-mypy@v0.4.2...v0.5.0)

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

test-requirements.txt

@@ -16,6 +16,7 @@ coveralls==1.11.1
 django==3.0.3
 docopt==0.6.2             # via coveralls
 entrypoints==0.3          # via flake8
+filelock==3.0.12          # via pytest-mypy
 flake8==3.7.9             # via pytest-flake8
 h11==0.9.0                # via httpx, uvicorn
 h2==3.2.0                 # via httpx
@@ -42,7 +43,7 @@ pytest-cov==2.8.1
 pytest-django==3.8.0
 pytest-flake8==1.0.4
 pytest-mock==2.0.0
-pytest-mypy==0.4.2
+pytest-mypy==0.5.0
 pytest-sugar==0.9.2
 pytest==5.3.5
 pytz==2019.3              # via django