Include InfluxDB/Grafana

cc @yorickpeterse

• two daemons: influxdb, grafana
• influxdb needs config, listens on UDP port
• grafana is Go app, listen on TCP port
• grafana needs SQL backend, should reuse Postgres
• grafana dashboards are in https://gitlab.com/gitlab-org/grafana-dashboards/tree/master ; import needs API token
• question: how to set up grafana user account, API token for automatic import etc.