add dns_servers to data model and tosca for VSGService
diff --git a/xos/services/cord/models.py b/xos/services/cord/models.py
index 959bf19..37ee78e 100644
--- a/xos/services/cord/models.py
+++ b/xos/services/cord/models.py
@@ -402,7 +402,8 @@
                           ("backend_network_label", "hpc_client"),
                           ("wan_container_gateway_ip", ""),
                           ("wan_container_gateway_mac", ""),
-                          ("wan_container_netbits", "24") )
+                          ("wan_container_netbits", "24"),
+                          ("dns_servers", "8.8.8.8") )
 
     def __init__(self, *args, **kwargs):
         super(VSGService, self).__init__(*args, **kwargs)