This key is no more send by vidjil metrics.

Merge branch 'merge-metrics-instance' of gitlab.inria.fr:vidjil/metrics/metrics-server into merge-metrics-instance

Create a log directory for metrics

More common case is to hide metrics user login

As this service should be launched on target server, move it inside a dedicated compose file

All data will be serve with no security.
be removing port, data will be only accesible inside metrics docker network

Old data ofn vidjil server have no provider field filled, and sizes where not corectly computed. In this case, value is none and can't be interpreted by metrics.

No default password for grafana
Remove useless dev entry for prometheus