Deprication warnings from TaskFlow

[Michal Dulko]

There are two TaskFlow's deprecation warnings in Cinder logs:

/opt/stack/cinder/cinder/flow_utils.py:66: DeprecationWarning: Class 'taskflow.listeners.base.ListenerBase' has moved to 'taskflow.listeners.base.Listener' in version '0.6' and will be removed in a future version
  flow_listen_for=flow_listen_for)

/opt/stack/cinder/cinder/flow_utils.py:91: DeprecationWarning: Class 'taskflow.utils.misc.Failure' has moved to 'taskflow.types.failure.Failure' in version '0.6' and will be removed in a future version
  if isinstance(result, misc.Failure):

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/149217

[OpenStack Infra (hudson-openstack)]

Change abandoned by Michal Dulko (<email address hidden>) on branch: master
Review: https://review.openstack.org/149217
Reason: 149374 got merged with the same changes.

[Michal Dulko (michal-dulko-f)]

https://review.openstack.org/#/c/149374/ got merged.