Add post job to create _member_ role

In OpenStack deployment it's expected to have _member_ role.
For example, you'll not be able to change quotas w/o this role
in Horizon.

Change-Id: Ief0c4d75d7409c4ea38982f017f7b1694c452369

service/keystone.yaml

@@ -58,6 +58,9 @@ service:
         - name: keystone-create-project
           type: single
           command: openstack project create service
+        - name: keystone-create-role-member
+          type: single
+          command: openstack role create _member_
 
 files:
   keystone-conf: