DodoApp: Introduce password role

Auto generate passwords for PostgreSQL and MongoDB.

Change-Id: Ibd9fb900ddc8dd505c60ae4dfba73f1c951e3470
diff --git a/core/installer/app_manager.go b/core/installer/app_manager.go
index a4140c0..8257d27 100644
--- a/core/installer/app_manager.go
+++ b/core/installer/app_manager.go
@@ -1279,6 +1279,8 @@
 		return []string{}
 	case KindCluster:
 		return []string{}
+	case KindPassword:
+		return []string{}
 	default:
 		panic("MUST NOT REACH!")
 	}