Generate random keystone users

Change-Id: I8dbd07b10d29b43d1c35fa76bcaa0f0efb32beda
Related-Prod: PROD-29868
diff --git a/keystone/client/v3/service/heat.yml b/keystone/client/v3/service/heat.yml
index 54c8f0b..2163292 100644
--- a/keystone/client/v3/service/heat.yml
+++ b/keystone/client/v3/service/heat.yml
@@ -14,6 +14,7 @@
               enabled: true
           users:
             heat:
+              name: ${_param:keystone_heat_username}
               password: ${_param:keystone_heat_password}
               email: ${_param:admin_email}
               options: ${_param:openstack_service_user_options}