Update shallowCopy() to work with the newer version of image.
Remove things from Push() that we don't need to do any more.
Preserve digests in image names, make sure we update creation times, and
add a test to ensure that we can pull, commit, and push using such names
as sources.
Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>
Closes: #187
Approved by: rhatdan
