Bump pytest-cov from 2.11.0 to 2.11.1

Bumps [pytest-cov](https://github.com/pytest-dev/pytest-cov) from 2.11.0 to 2.11.1.
- [Release notes](https://github.com/pytest-dev/pytest-cov/releases)
- [Changelog](https://github.com/pytest-dev/pytest-cov/blob/master/CHANGELOG.rst)
- [Commits](https://github.com/pytest-dev/pytest-cov/compare/v2.11.0...v2.11.1)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

requirements-tests.txt

 -r requirements.txt
 pytest==6.2.1
-pytest-cov==2.11.0
+pytest-cov==2.11.1
 flake8==3.8.4
 pyflakes==2.2.0