docker-compose: use `sameersbn/postgresql:9.4-2`
docker-compose: use `sameersbn/postgresql:9.4-2`

youhong316/docker-gitlab-ci,sameersbn/docker-gitlab-ci,bboehmke/docker-gitlab-ci,bboehmke/docker-gitlab-ci,adiferd/docker-gitlab-ci,adiferd/docker-gitlab-ci,sameersbn/docker-gitlab-ci,youhong316/docker-gitlab-ci