* Containerd: download containerd from upstream instead of using distro specific packages
split runc download to separate role
make bootstrap-os role deploy container-selinux and seccomp libraries
clean up package manager provided containerd
move variables to docker role that are no longer common with containerd
* Containerd: make molecule testing more relevant
* replace ubuntu18 with ubuntu20
* add centos8 and debian11 to molecule tests
* run kubernetes/preinstall role to ensure relevancy
of test including dependency packages
* CI: adjust test scenarios for downloaded containerd
This replaces kube-master with kube_control_plane because of [1]:
The Kubernetes project is moving away from wording that is
considered offensive. A new working group WG Naming was created
to track this work, and the word "master" was declared as offensive.
A proposal was formalized for replacing the word "master" with
"control plane". This means it should be removed from source code,
documentation, and user-facing configuration from Kubernetes and
its sub-projects.
NOTE: The reason why this changes it to kube_control_plane not
kube-control-plane is for valid group names on ansible.
[1]: https://github.com/kubernetes/enhancements/blob/master/keps/sig-cluster-lifecycle/kubeadm/2067-rename-master-label-taint/README.md#motivation
