Update pytest-cov requirement from ==2.10.* to >=2.10,<2.12

Updates the requirements on [pytest-cov](https://github.com/pytest-dev/pytest-cov) to permit the latest version.
- [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@v2.10.0...v2.11.1)

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

setup.py

@@ -38,7 +38,7 @@ def read(*parts):
 tests_require = [
     'codecov==2.1.*',
     'coverage>=5.3,<5.6',
-    'pytest-cov==2.10.*',
+    'pytest-cov>=2.10,<2.12',
     'pytest>=6.1,<6.3',
     'pycodestyle>=2.6,<2.8'
 ]