Add GitLab CI configuration
Add GitLab CI configuration which matrix tests against supported Django and Python versions.
We are aware of a potential issue with using some sha256 digest to pull docker images (e.g. docker pull registry.gitlab.developers.cam.ac.uk/path/to/image@sha256:5e85dd....). Please use a tag or the most recent manifest digest.
Add GitLab CI configuration which matrix tests against supported Django and Python versions.