Allow keystone v3 in the designate driver

[OpenStack Infra]

https://review.openstack.org/398359
Dear bug triager. This bug was created since a commit was marked with DOCIMPACT.
Your project "openstack/neutron" is set up so that we directly report the documentation bugs against it. If this needs changing, the docimpact-group option needs to be added for the project. You can ask the OpenStack infra team (#openstack-infra on freenode) for help if you need to.

commit 91d048dbde83a52f43aceebaf1b1e1ef0937602d
Author: Gyorgy Szombathelyi <email address hidden>
Date: Wed Nov 16 14:37:38 2016 +0100

    Allow keystone v3 in the designate driver

    Using the loader from keystoneauth1, it is possible to easily use
    keystone v3 options in [designate].
    For the end user, it means she/he must specify designate.auth_type,
    then she/he can specify an Keystone v3 endpoint in designate.auth_url.

    Change-Id: I8bb02f11e60767dacdf6ac852979cfa82de1e08b
    Closes-bug: #1585976
    DocImpact

[Boden R (boden)]

Based on what I'm seeing, we should update [1] to include the ability to keystone v3 in the [designate] config. See change for more details.

Moving this to openstack-manuals as I don't see any docs in the neutron repo that need updating as a part of this.

[1] http://docs.openstack.org/newton/networking-guide/config-dns-int.html#configuring-openstack-networking-for-integration-with-an-external-dns-service