Better organize the tox.ini passenv vars
Better organize the tox.ini passenv vars

 - Adds entries for testr env vars that control logging
 - Vertically aligns to improve diffs in the future.
 - Sorts in alpha order

Change-Id: I3825151a6927fb7227a2861be72014b7bed32b13

openstack/designate,openstack/designate,openstack/designate