* Adds two new experimental jobs (Designate+Bind9/PowerDNS)
* Does not restrict execution branch yet, we'll want this to
be Neuton+ as it moves over the check/gate queues. For now,
i'd like to see just how badly the remaining changes below
fail on other branches, as we may choose to include these
on Mitaka.
* Replaces use of the gate / pre test / post tests hooks, as
enough configurability is now exposed.
* Uses tempest in "all-plugin" mode, limiting to all tests
containing "designate" in the name. Ideally, this would be
changed to "full-plugin" mode, without the designate
restriction, but this does not exist in tempest's tox.ini
* Attempts to be ready to add stable branch editions of this
this using branch-override and job-suffix.
Change-Id: I8166d447802b4520c0721b9f006b59543b3b548c
5118c6fed7