Add docker.client classes to k8s models

Change-Id: I5d0657aef89028d83bb56fda1d83f717d0fb7a8e
diff --git a/classes/cluster/sl_k8s_contrail/stacklight/client.yml b/classes/cluster/sl_k8s_contrail/stacklight/client.yml
index 0f45d40..6cb2915 100644
--- a/classes/cluster/sl_k8s_contrail/stacklight/client.yml
+++ b/classes/cluster/sl_k8s_contrail/stacklight/client.yml
@@ -1,4 +1,5 @@
 classes:
+- system.docker.client
 - system.elasticsearch.client.single
 - system.grafana.client
 - system.grafana.client.datasource.prometheus