Update pytest-mock requirement from ~=3.3.1 to ~=3.4.0
Update pytest-mock requirement from ~=3.3.1 to ~=3.4.0

Updates the requirements on [pytest-mock](https://github.com/pytest-dev/pytest-mock) to permit the latest version.
- [Release notes](https://github.com/pytest-dev/pytest-mock/releases)
- [Changelog](https://github.com/pytest-dev/pytest-mock/blob/master/CHANGELOG.rst)
- [Commits](https://github.com/pytest-dev/pytest-mock/compare/v3.3.1...v3.4.0)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
ariebovenberg/snug,ariebovenberg/omgorm