* Apply "become" on roles instead of plays
This leads to facts being gathered for the "regular" login user, instead
of root.
* Do not rely on ansible_user
Instead of reading ansible_user (which may or may not be defined), this
patch lets the roles rely on Ansible facts [1].
[1]: https://docs.ansible.com/ansible/latest/playbook_guide/playbooks_vars_facts.html
* Test cluster using molecule
* Fix detection of first control node
* Include --flannel-iface and --node-ip as k3s arguments
* Store logs of k3s-init.service as GitHub job artifacts
