No need to expose the postgres port

There is no need to expose the port to the host, all container will be
running in the same network, so they will have access to database port.

compose.yaml

@@ -5,8 +5,6 @@ services:
     environment:
       POSTGRES_PASSWORD: f00d
       POSTGRES_USER: ofn
-    ports:
-      - 5432:5432
     volumes:
       - 'postgres:/var/lib/postgresql/data'
   redis: