All stable charm specs failing on KeyError: 'preferred-api-version' in helper/setup/utils/mojo_utils.py

[Ryan Beisner]

Mojo spec helpers and tests were updated to pivot keystone auth on existence of a new charm config option which only exists in the next/master charms. This causes the post-deployment spec helpers to trace in a few places when exercising the stable charm set.

Test automation is switched to run on the linked branch, pending review and landing.

@ Rev253, all stable charm mojo spec test automation is failing on:

00:32:17.969 Traceback (most recent call last):
00:32:17.969 File "/srv/mojo/mojo-openstack-specs/trusty/osci-mojo/spec/specs/full_stack/stable_deploy/kilo/network_setup.py", line 106, in <module>
00:32:17.969 sys.exit(main(sys.argv))
00:32:17.969 File "/srv/mojo/mojo-openstack-specs/trusty/osci-mojo/spec/specs/full_stack/stable_deploy/kilo/network_setup.py", line 102, in main
00:32:17.969 setup_sdn(net_topology, net_info)
00:32:17.969 File "/srv/mojo/mojo-openstack-specs/trusty/osci-mojo/spec/specs/full_stack/stable_deploy/kilo/network_setup.py", line 10, in setup_sdn
00:32:17.969 overcloud_novarc = mojo_utils.get_overcloud_auth()
00:32:17.969 File "/srv/mojo/mojo-openstack-specs/trusty/osci-mojo/spec/helper/setup/utils/mojo_utils.py", line 283, in get_overcloud_auth
00:32:17.969 if juju_get('keystone', 'preferred-api-version') == 2:
00:32:17.969 File "/srv/mojo/mojo-openstack-specs/trusty/osci-mojo/spec/helper/setup/utils/mojo_utils.py", line 227, in juju_get
00:32:17.969 if 'value' in service_config['settings'][option]:
00:32:17.969 KeyError: 'preferred-api-version'