Test end to end.

[mrzzy]

We should add end to end tests to ensure that each component functions correctly as a whole.

What should be included the end to end test:

• deploy k8s-cms with helm chart and docker-compose

Perhaps we can use k3s of a full blown k8s cluster

• use kcmscli to import users from CSV
• use kcmscli to import mock contest to k8s-cms via k8s-cms master.
• use selenium to simulate a user creating a wrong submission.
• use selenium to simulate creating a correct submission.

Part of #2