Fix tests by moving them to Github actions and making them compatible with the latest version of molecule

[woodrad]

The current test suite is failing for two reasons:

1. molecule had breaking API changes. Because this project is not version locked on a specific version of molecule, this means that parts of the test suite are bound to have troubles.
2. Even if there were no troubles running tests on Travis, their new limitations on execution time and number of executions would make testing use Travis untenable. The best option is to move to GitHub Actions. Jeff Geerling has some good examples in his repositories. ansible-role-docker might be a good starting point.