The change modifies the keystone template tasks such that it's now
using the config_template action plugin. This change will make so that
config files can be dynamically updated, by a deployer, at run time,
without requiring the need to modify the in tree templates or defaults.
Partially implements: blueprint tunable-openstack-configuration
Change-Id: I957d55df81c7edd4e2a95597a62a75c6bd0f46fe
f38241e671