Feature/OIDC

[bart-maykin]

fixes #3

[stevenbal]

Currently logging in with OIDC doesn't work, because the following line is missing from the AUTHENTICATION_BACKENDS:

"mozilla_django_oidc_db.backends.OIDCAuthenticationBackend",

Please make sure to test it locally if it works, in the repo of mozilla-django-oidc-db there is a docker compose setup you can use to run Keycloak as an identity provider: https://github.com/maykinmedia/mozilla-django-oidc-db/tree/master/docker

If you get that container running and set the following settings in the Referentielijsten admin (OIDC config), it should be possible to test this locally:

[stevenbal]

Also I see that the tests in CI seem to be skipped, so there's probably something going wrong in the GH actions setup?

[Coperh]

Other than the things Steven caught (which I probably would not have), looks good.

Appears on the login page and styling works.