Replaced underscores with hyphens in cluster names and domains

Change-Id: I90d163602a0915b23f25f9f4d799799c0336e664
diff --git a/classes/cluster/sl-k8s-contrail/infra/init.yml b/classes/cluster/sl-k8s-contrail/infra/init.yml
index 9e7f58d..0b58654 100644
--- a/classes/cluster/sl-k8s-contrail/infra/init.yml
+++ b/classes/cluster/sl-k8s-contrail/infra/init.yml
@@ -11,7 +11,7 @@
     infra_config_deploy_address: 192.168.10.90
 
     cluster_domain: sl-k8s-contrail.local
-    cluster_name: sl_k8s_contrail
+    cluster_name: sl-k8s-contrail
     apt_mk_version: nightly
   linux:
     network: