Merge from oslo-incubator for notifier

Goal: merge oslo-incubator change
I282d4ae3311bc3fcda6be8e5a1fceecfc8ddb115

Done via:
python update.py --nodeps --base cinder --dest-dir ../cinder \
 --modules notifier

Change-Id: I0cb982b3b45eb63941f9bfe5407c93af280c452a
Merge "Merge from oslo-incubator for notifier"