Add NovaInstanceWithCinderVolume_Native F18 HOT template.

A template showing how to create a Nova instance, a Cinder volume and attach
the volume to the instance using Cinder VolumeAttachment.
The template uses only Heat OpenStack native resource types.

Change-Id: I07459a76a4ae859e53185c273d1f20a3985cc74d
Merge "Add NovaInstanceWithCinderVolume_Native F18 HOT template."