release 0.4.0
release 0.4.0

jhamrick/dockerspawner,Fokko/dockerspawner,quantopian/dockerspawner,jhamrick/dockerspawner,Fokko/dockerspawner,jupyter/dockerspawner,quantopian/dockerspawner,jupyter/dockerspawner,minrk/dockerspawner,minrk/dockerspawner