Kubernetes Dashboard v1.7.1 Refactor

This version required changing the previous access model for dashboard completely but it's a change for the better. Docs were updated.

* New login/auth options that use apiserver auth proxying by default
* Requires RBAC in `authorization_modes`
* Only serves over https
* No longer available at https://first_master:6443/ui until apiserver is updated with the https proxy URL:
* Can access from https://first_master:6443/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy/#!/login you will be prompted for credentials
* Or you can run 'kubectl proxy' from your local machine to access dashboard in your browser from: http://localhost:8001/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy/
* It is recommended to access dashboard from behind a gateway that enforces an authentication token, details and other access options here: https://github.com/kubernetes/dashboard/wiki/Accessing-Dashboard---1.7.X-and-above

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

@@ -78,3 +78,10 @@
     that: ansible_swaptotal_mb == 0
   when: kubelet_fail_swap_on|default(true)
   ignore_errors: "{{ ignore_assert_errors }}"
+
+
+- name: Stop if RBAC is not enabled when dashboard is enabled
+  assert:
+    that: rbac_enabled
+  when: dashboard_enabled
+  ignore_errors: "{{ ignore_assert_errors }}"