Monitoring promise break instanciation:
  UserError: No section named 'monitor-base-promise'

and telegraf startup script is using influxdb promise, because it has a
bug that it needs to start only after influxdb is available, so it does
not look so easy to switch to monitoring stack.

Also, this software is experimental (and also is conceptually a
monitoring software on its own), so it does not need monitoring for now.

This reverts commit 48b6c27c.

This enable vieiwing applications logs directly in grafana, as long as
loki agent can access the log file and the regular expressions to parse
the logs are defined

Other changes:
 - provision data sources automatically so that user do not have to add
   them manually
 - update TODO in README
 - introduce a SR test
 - switch to dep to install dependencies, because that's how these
  packages manage their dependencies.

Versions up:
  grafana: v6.3.0
  telegraf: v1.11.1-0
  influxdb: v1.7.8rc1
New:
  loki: v0.3.0