Revert "Add openSUSE support" (#2697)

.gitlab-ci.yml

README.md

Vagrantfile

docs/opensuse.md

roles/bootstrap-os/tasks/bootstrap-opensuse.yml

roles/bootstrap-os/tasks/main.yml

roles/docker/tasks/main.yml

roles/docker/templates/docker.service.j2

roles/docker/vars/suse.yml

roles/etcd/tasks/upd_ca_trust.yml

roles/kubernetes/preinstall/defaults/main.yml

roles/kubernetes/preinstall/tasks/main.yml

roles/kubernetes/preinstall/tasks/verify-settings.yml

roles/kubernetes/preinstall/vars/suse.yml

roles/kubernetes/secrets/tasks/upd_ca_trust.yml

roles/rkt/tasks/install.yml

roles/rkt/vars/suse.yml

tests/files/gce_opensuse-canal.yml