This change adds a few checks after the deployment of the
InfluxDB/Grafana plugin:
- Check that authorized users can access the API (InfluxDB and Grafana)
- Check that unauthorized users can't access the API (InfluxDB and
Grafana)
- Check that the root user can login and has admin rights (InfluxDB)
- Check that the login page is accessible (Grafana)
Change-Id: I1fa49469f71b2d1cd3e99bac76de81f3f7a68c2b