Uses a self signed cert, not for production use.
$ docker-compose up
$ docker run -it --network host --rm postgres:9.6 psql -h localhost -U postgres -p 5434 template1 $ docker run -it --network host --rm postgres:9.5 psql -h localhost -U postgres -p 5433 template1 $ docker run -it --network host --rm postgres:9.4 psql -h localhost -U postgres template1