Add extra Ansible Variable perameter
Add extra Ansible Variable perameter

This change adds an extra ansible host var to the defaults which
will allow an operator to more easily define a mapping of options
to configure advanced ansible options within their deployment.

Change-Id: If4654470a77a67445a56fb8fed6963fed300aad4
Signed-off-by: Kevin Carter <1d9a750a4fc7026fb02029431dc8a87d24487135@redhat.com>

openstack/tripleo-heat-templates,openstack/tripleo-heat-templates