barbican_tempest_plugin.tests.scenario.test_volume_encryption failing on periodic-tripleo-ci-centos-7-multinode-1ctlr-featureset017-master

Logs:
https://logs.rdoproject.org/openstack-periodic/periodic-tripleo-ci-centos-7-multinode-1ctlr-featureset017-master/519da2f/tempest.html.gz

Failure:
ft1.1: setUpClass (barbican_tempest_plugin.tests.scenario.test_volume_encryption.VolumeEncryptionTest)_StringException: Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/tempest/test.py", line 172, in setUpClass
    six.reraise(etype, value, trace)
  File "/usr/lib/python2.7/site-packages/tempest/test.py", line 162, in setUpClass
    cls.setup_clients()
  File "/usr/lib/python2.7/site-packages/barbican_tempest_plugin/tests/scenario/barbican_manager.py", line 67, in setup_clients
    super(BarbicanScenarioTest, cls).setup_clients()
  File "/usr/lib/python2.7/site-packages/barbican_tempest_plugin/tests/scenario/manager.py", line 82, in setup_clients
    cls.volumes_client = cls.os_primary.volumes_client
AttributeError: 'Manager' object has no attribute 'volumes_client'