Updated openstack/openstack
Project: openstack/keystone  4a1ce01ab3f5987ffbf10576ae1351bc65ba2783
null
Add ABCMeta metaclass to token provider

Use the abc module for managing abstract base classes in the driver
layer.

bp: abstract-base-class-drivers
Change-Id: I4af9752a82c9be5ef95b41593e430de36d25c569