PROD-1221: Don't expose postgres port externally

docker-compose.yml

@@ -20,8 +20,8 @@ services:
     container_name: nantum-vtn-db
     expose:
       - 5432
-    ports:
-      - 55432:5432
+#    ports:
+#      - 55432:5432
     image: postgres:9.5
     volumes:
       - postgres_data:/var/lib/postgresql/data