Previous work on Watcher added the Docker images, this
change adds the ansible configuration.

There is support for HA, via haproxy to balance across the
Watcher API hosts.

There is also a hook into nova.conf to conditionally add
Nova compute Host metrics via Ceilometer if Watcher is enabled.

This defaults to enabled false.

Change-Id: I8763528bb6ff12943b810212c71396d2d7cf6836
Partial-bug: #1598929
Partially-implements: bp watcher
Signed-off-by: Dave Walker (Daviey) <email@daviey.com>