- Caching the entire virtualenv in Travis CI has proven to cause issues, caching just pip's cache directory.

- Use privileged container instead of just adding the sys_admin capability (the latter has been shown to be cause unrelated issues).

- Remove mention of tests/requirements.yml from the Requirements section in the README, relevant only for testing.

accordingly.

- Add pre-commit check for out-of-date dependencies.
- Add flake8 pre-commit check.
- List roles needed for testing (bootstraping) at
tests/requirements.yml, leave other dependencies at meta/main.yml.
- Update molecule.yml, ansible.cfg for newer versions of Molecule.
- Update documentation, playbook accordingly.

  issues:
  - Missed a blank line between tests in `tests/test_example.py`.
  - Named the assertions task.
- Updated the OpenBSD Vagrant box to 6.0, updated assertion accordingly.