Add node_group_checks to openshift_node_group.yml

Validate openshift_node_groups and openshift_node_group_name

playbooks/openshift-master/private/openshift_node_group.yml

@@ -2,7 +2,13 @@
 - name: Configure node configmap on the master
   hosts: oo_first_master
   gather_facts: no
+  roles:
+  - role: openshift_facts
+  - role: lib_utils
   tasks:
+  # node_group_checks is a custom action plugin defined in lib_utils.
+  - name: Validate openshift_node_groups and openshift_node_group_name
+    node_group_checks: {}
   - name: include openshift node config
     import_role:
       name: openshift_node_group