Reduce service user permissions

Most of the services create the service user with the admin permission.
This is unnecessary for token validation and they should be restricted
to only having the service role.

Change-Id: Id7a9366d2c6a36139240f64371002362dc2d8d3b
diff --git a/lib/cinder b/lib/cinder
index 12ba51e..17a0cc3 100644
--- a/lib/cinder
+++ b/lib/cinder
@@ -333,7 +333,7 @@
     # Cinder
     if [[ "$ENABLED_SERVICES" =~ "c-api" ]]; then
 
-        create_service_user "cinder" "admin"
+        create_service_user "cinder"
 
         if [[ "$KEYSTONE_CATALOG_BACKEND" = 'sql' ]]; then