Re-implement Hydra, Kratos and SSO e2e test
The tests were never really reliable. When implementing #132 (closed) it completely broke. They need to be re-implemented in a way that doesn't use GitLab CI services.
The problem with GitLab CI services is that we can't control in which order they get started. When the services don't start quick enough, they get stopped and they don't work. That's why the tests keep failing (see !92 (merged) for the failed jobs)