Updated openstack/openstack
Project: openstack/python-keystoneclient  dd5260b3deebeb32d31fb3a3c31d3a6604ef29e5

Add invalidate doc string to identity plugin

This was simply copied and pasted from the abstract method it overrides.

Change-Id: Ica349e7302434be43e08fc272e8fce5699553d9a