Revert "Use K8s 1.14 and add kubeadm experimental control plane mode (#4317)" (#4510)

README.md

inventory/sample/group_vars/k8s-cluster/k8s-cluster.yml

roles/download/defaults/main.yml

roles/kubernetes/client/tasks/main.yml

roles/kubernetes/kubeadm/tasks/main.yml

roles/kubernetes/master/defaults/main/kube-proxy.yml

roles/kubernetes/master/defaults/main/main.yml

roles/kubernetes/master/tasks/kubeadm-certificate.yml

roles/kubernetes/master/tasks/kubeadm-kubeconfig.yml

roles/kubernetes/master/tasks/kubeadm-migrate-certs.yml

...ubernetes/master/tasks/kubeadm-secondary-experimental.yml

roles/kubernetes/master/tasks/kubeadm-secondary-legacy.yml

roles/kubernetes/master/tasks/kubeadm-setup.yml

roles/kubernetes/master/tasks/kubeadm-version.yml

roles/kubernetes/master/tasks/pre-upgrade.yml

...bernetes/master/templates/kubeadm-config.v1alpha1.yaml.j2

...bernetes/master/templates/kubeadm-config.v1alpha2.yaml.j2

...bernetes/master/templates/kubeadm-config.v1alpha3.yaml.j2

...ubernetes/master/templates/kubeadm-config.v1beta1.yaml.j2

...tes/master/templates/kubeadm-controlplane.v1beta1.yaml.j2