[CORD-2889]
Change to using premade `postgres` container

Change-Id: I3f4dc65d7b6957cbd9b8b7d5d3dc23045d4b1a82
diff --git a/scenarios/mock/config.yml b/scenarios/mock/config.yml
index ce0d91b..67bd937 100644
--- a/scenarios/mock/config.yml
+++ b/scenarios/mock/config.yml
@@ -72,8 +72,9 @@
   - "xosproject/xos-ws"
   - "xosproject/chameleon"
   - "nginx"
-  - "redis"
   - "node"
+  - "postgres"
+  - "redis"
 
 # Ansible Inventory
 inventory_groups: