Remove local port binding for postgres in dev env

I dont think we need to bind this port at the host level. This will allow us to
run the galaxy_ng dev tooling side-by-side with AWX.

tools/docker-compose.yml

@@ -46,8 +46,6 @@ services:
   postgres:
     image: postgres:10
     container_name: tools_postgres_1
-    ports:
-      - "5432:5432"
     environment:
       POSTGRES_HOST_AUTH_METHOD: trust
     volumes: