Move revoke extension into core

[OpenStack Infra]

https://review.openstack.org/235704
commit 32b70d15c457670b10e83e358c0f2e89bea40e95
Author: Steve Martinelli <email address hidden>
Date: Thu Oct 15 22:21:11 2015 -0400

    Move revoke extension into core

    Remove revoke as an extension and move it to a core resource.
    For now we leave the database migrations in the extension directory
    until we have a general policy for merging these into core.

    DocImpact: update keystone-paste and remove revoke from pipeline

    Change-Id: I2d6f425a508b7acb4b4d079e4387f25bf7555683
    Implements: bp move-extensions

[Joseph Robinson (joseph-r-email)]

Affects the install guide: http://docs.openstack.org/liberty/install-guide-rdo/keystone-install.html

Mentioned in the developer docs: http://docs.openstack.org/developer/keystone/extensions/revoke-configuration.html

Also mentioned in developer docs source code:
http://docs.openstack.org/developer/keystone/kilo/_modules/keystone/contrib/revoke/core.html
http://docs.openstack.org/developer/keystone/_modules/keystone/revoke/routers.html