Instead of creating a deployment with a replica set, we just create the
pod once. Also the pod should have everything in the future to run the
database migration. Ie. have `cypher-shell` to write directly to the
database in the current network. All required configuration is passed
manually to the `db-migration-worker`-pod directly. SSH-keys are copied
through a secrets file. This altogether made many configuration files
obsolete.
I think this is better. For development it might be interesting to have
access to the backend but I think one should do development with
docker-compose not minikube and such.
