Use templates for cover and lower-constraints
Use templates for cover and lower-constraints

Use openstack-tox-cover template, this runs the cover job as
non-voting in the check queue only.

Use openstack-lower-constraints-jobs template

Remove jobs that are part of the templates.

Reorder templates alphabetically.

Also, add repo to designate queue for co-gating.

Change-Id: I8cd7ec2e27e3e15c92a9f57f98117eca006059b1

openstack/python-designateclient