There is no usecase for having 2 endpoints that have the same Region,
interface, service_name and service_type.
The keystone module should default to update these endpoints if the url
is different, but the Region, interface, service_name and service_type
match.
This will make the default behaviour of state "present" to match that of
state "update".
Change-Id: I0ade538e20f2a926b33c1637446c2d4f650cd13d
5822e29d41