Update the image addresses in .gitlab-ci.yml from "duneci/dune:***" to...

Update the image addresses in .gitlab-ci.yml from "duneci/dune:" to "registry.dune-project.org/docker/ci/dune:", so the dokcer-images are fetched from the official dune-ci

@osander: As discussed: update the addresses

This still fails, due to @jaap 's recent changes to dune-elasticity. In particular, some of the energy implementations have been moved out of the Elasticity namespace, and you need to adapt your code accordingly.

See !38 (closed)

closed

reopened

restored source branch fix/ci-docker-addresses

mentioned in merge request !38 (closed)

merged

mentioned in commit 82340f3e