Fix failed Contrail RBAC Tempest testcases (#5)

This commit fixes issues found for US441924.
The fixes are against Contrail 5.0.1.

Change-Id: I94bc166ad9038087eb4839881f44c6f6d00b6c99
diff --git a/tungsten_tempest_plugin/config.py b/tungsten_tempest_plugin/config.py
index b82299e..4fd1bb7 100644
--- a/tungsten_tempest_plugin/config.py
+++ b/tungsten_tempest_plugin/config.py
@@ -35,6 +35,9 @@
     cfg.StrOpt('catalog_type',
                default='sdn-l-config',
                help="Catalog type of the SDN service"),
+    cfg.StrOpt('contrail_version',
+               default='5.0',
+               help="Version of SDN service"),
 ]
 
 tungsten_log_group = cfg.OptGroup(