docker-compose exec and docker-compose slow are slow, use docker instead

[alberto56]

This is slow:

docker-compose exec a /bin/bash -c 'echo "hello"' docker-compose port a 80

This is faster:

A=$(docker-compose ps -q a) docker exec $A /bin/bash -c 'echo "hello"' docker post $A 80

[alberto56]

See https://github.com/docker/compose/issues/4748, we could gain some speed here.