Very basic image resource

All I've tried with this resource is listing so far.  I don't
see why some other operations wouldn't work, but I want to get
this in to get things rolling.

To run the example:

python -m examples.list openstack.image.v1.image.Image

Change-Id: Ia341c8bc2a914e38b96a67a21efb40ad8cf4e93c
Merge "Very basic image resource"