included service.maas.cluster.single

Change-Id: Ic133d006a448b51de0b74dc49123c8d81f86ebbc
diff --git a/maas/region/single.yml b/maas/region/single.yml
index d3227ca..2bf9469 100644
--- a/maas/region/single.yml
+++ b/maas/region/single.yml
@@ -1,5 +1,6 @@
 classes:
   - service.maas.region.single
+  - service.maas.cluster.single
   - service.maas.region.vendor_repo
 parameters:
   _param: