Bump pytest-cov from 2.9.0 to 2.10.0

Bumps [pytest-cov](https://github.com/pytest-dev/pytest-cov) from 2.9.0 to 2.10.0.
- [Release notes](https://github.com/pytest-dev/pytest-cov/releases)
- [Changelog](https://github.com/pytest-dev/pytest-cov/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest-cov@v2.9.0...v2.10.0)

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

requirements-test.txt

@@ -1,7 +1,7 @@
 # test runs requirements (versions we'll be testing against) - automatically updated by requires.io
 pytest==5.4.3
 pytest-xdist==1.32.0
-pytest-cov==2.9.0
+pytest-cov==2.10.0
 coverage==5.1 # pytest-cov
 mock==4.0.2
 port-for==0.4