Add test for creating service with env
Add test for creating service with env

Signed-off-by: Simon Li <3c28b498b783fff544f4f35f4d01dd7d8e101746@gmail.com>

funkyfuture/docker-py,auready/docker-py,vpetersson/docker-py,youhong316/docker-py,kaiyou/docker-py,vdemeester/docker-py,vdemeester/docker-py,docker/docker-py,auready/docker-py,kaiyou/docker-py,docker/docker-py,youhong316/docker-py,vpetersson/docker-py,funkyfuture/docker-py,dimaspivak/docker-py,dimaspivak/docker-py