Update keystone sanity check to use built in shade

The current module 'kolla_sanity' was written as a shim before full
shade support was added to Ansible. This should now no longer be needed,
we can implement the checks using Ansible provided modules.

Begin by updating the Keystone check to use 'os_auth' to fetch a token,
I think this is a good basic smoke test to verify Keystone is working.

Change-Id: I16049d9201fd8138c781ef2e1e0c1827ea817259
Partially-implements: blueprint sanity-check-container

ansible/roles/keystone/tasks/check.yml

 ---
 - name: Keystone sanity checks
-  command: docker exec -t kolla_toolbox /usr/bin/ansible localhost
-    -m kolla_sanity
-    -a "service=keystone
-        project=service
-        user=admin
-        password={{ keystone_admin_password }}
-        role=admin
-        region_name={{ openstack_region_name }}
-        auth={{ '{{ openstack_keystone_auth }}' }}"
-    -e "{'openstack_keystone_auth':{{ openstack_keystone_auth }}}"
-  register: keystone_sanity
-  changed_when: "{{ keystone_sanity.stdout.find('localhost | SUCCESS => ') != -1 and (keystone_sanity.stdout.split('localhost | SUCCESS => ')[1]|from_json).changed }}"
-  until: keystone_sanity.stdout.split()[2] == 'SUCCESS'
-  retries: 10
-  delay: 5
+  kolla_toolbox:
+    module_name: os_auth
+    module_args:
+      auth: "{{ openstack_keystone_auth }}"
   run_once: True
+  delegate_to: "{{ groups['keystone'][0] }}"
   when: kolla_enable_sanity_keystone | bool