Update policy_types documentation
Update policy_types documentation

The policy_types document is old, this patch updates
it.

Change-Id: I46ae0e575f7a96fd2b1c0017e993869355fa530d

Alzon/senlin,openstack/senlin,Alzon/senlin,tengqm/senlin-container,stackforge/senlin,openstack/senlin,openstack/senlin,stackforge/senlin,tengqm/senlin-container