Add support for resource_types

This adds the following commands:
$ heat resource-type-list
$ heat resource-type-show <resource type>

Change-Id: Ifa70da5bc56a5f2979697a9ce2c41fa9a5c1f947
Closes-bug: #1260130
(cherry picked from commit b14697ea3fada6e9f6725fa14e9c669beebd8875)

Conflicts:
	heatclient/v1/client.py