Remove Kubernetes <1.16 conditionals (#6088)

roles/download/templates/kubeadm-images.yaml.j2

roles/kubernetes/kubeadm/tasks/main.yml

...ernetes/kubeadm/templates/kubeadm-client.conf.v1alpha1.j2

...ernetes/kubeadm/templates/kubeadm-client.conf.v1alpha2.j2

...ernetes/kubeadm/templates/kubeadm-client.conf.v1alpha3.j2

...bernetes/kubeadm/templates/kubeadm-client.conf.v1beta2.j2

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

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

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

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

roles/kubernetes/node/tasks/kubelet.yml