Remove support for CoreOS Container Linux (#6576)

roles/etcd/meta/main.yml

roles/etcd/tasks/upd_ca_trust.yml

...s/external_provisioner/local_volume_provisioner/README.md

roles/kubernetes-apps/helm/tasks/install_host.yml

roles/kubernetes-apps/helm/tasks/main.yml

roles/kubernetes/node/tasks/install.yml

roles/kubernetes/preinstall/defaults/main.yml

roles/kubernetes/preinstall/handlers/main.yml

roles/kubernetes/preinstall/tasks/0020-verify-settings.yml

roles/kubernetes/preinstall/tasks/0040-set_facts.yml

roles/kubernetes/preinstall/tasks/0060-resolvconf.yml

roles/kubernetes/preinstall/tasks/0070-system-packages.yml

...ubernetes/preinstall/tasks/0080-system-configurations.yml

roles/kubernetes/preinstall/tasks/main.yml

roles/kubespray-defaults/defaults/main.yaml

roles/network_plugin/macvlan/handlers/main.yml

roles/network_plugin/macvlan/tasks/main.yml

roles/reset/tasks/main.yml

tests/cloud_playbooks/create-do.yml

tests/scripts/testcases_run.sh