Drop keystone dedicated ports

Those historic references to port 5000 and 35357 aren't being used
anymore for some time, so let us drop them.

Clean up some python2/3 wording along the way.

No longer mention Identity API v2, which is also a thing of the past.

Change-Id: Iafff097eee082f24ea2ae27ad038ad115aa36c61
6 files changed