This uses the Grafana container created with
Iddfafe852166fe95b3e433420e2e2a4a6380fc64 to run the
grafana.opendev.org service.

We retain the old model of an Apache reverse-proxy; it's well tested
and understood, it's much easier than trying to map all the SSL
termination/renewal/etc. into the Grafana container and we don't have
to convince ourselves the container is safe to be directly web-facing.

Otherwise this is a fairly straight forward deployment of the
container.  As before, it uses the graph configuration kept in
project-config which is loaded in with grafyaml, which is included in
the container.

Once nice advantage is that it makes it quite easy to develop graphs
locally, using the container which can talk to the public graphite
instance.  The documentation has been updated with a reference on how
to do this.

Change-Id: I0cc76d29b6911aecfebc71e5fdfe7cf4fcd071a4