Bump pytest from 5.2.0 to 6.2.4 (#760)

Bumps [pytest](https://github.com/pytest-dev/pytest) from 5.2.0 to 6.2.4.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/main/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@5.2.0...6.2.4)

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

requirements_dev_minimal.txt

@@ -5,4 +5,4 @@ numcodecs==0.8.0
 msgpack-python==0.5.6
 setuptools-scm==6.0.1
 # test requirements
-pytest==5.2.0
+pytest==6.2.4