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/sahara b/lib/sahara
index b3ca32f..db200cc 100644
--- a/lib/sahara
+++ b/lib/sahara
@@ -61,7 +61,7 @@
 # service     sahara    admin
 function create_sahara_accounts {
 
-    create_service_user "sahara" "admin"
+    create_service_user "sahara"
 
     if [[ "$KEYSTONE_CATALOG_BACKEND" = 'sql' ]]; then