Bump pytest-cov from 3.0.0 to 4.0.0

Bumps [pytest-cov](https://github.com/pytest-dev/pytest-cov) from 3.0.0 to 4.0.0. - [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@v3.0.0...v4.0.0) --- updated-dependencies: - dependency-name: pytest-cov dependency-type: direct:development update-type: version-update:semver-major ... Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]