Push docker images to docker hub

Ghost User
2018-12-14T16:08:57+01:00

### One-sentence description Push docker images to docker hub ### Why? Two reasons: * All our other docker images can be found on [Docker Hub](https://hub.docker.com/u/thalia/dashboard/) * Now we are public, we do not need the authentication of the Gitlab Registry. ### Current implementation We push to the Gitlab registry.