Change I2423030bd0849c051d22f63bf60b6a5f41f72574 migrated Federation
api-ref docs into keystone repository.
Moving Identity Provider API to its own file is one of the TODO
comments left there, which is being addressed in this change.
Change-Id: I5c5b26c2d4c9920d6b9642eaf0fc47ed5bffb3cb