subtests...save_load: Update test

*  Fixed location of saved image to use the automaticly cleaned
   temporary directory.

*  Updated all DockerCmd calls to pass the SubSubtest instance
   as the first parameter.

*  Removed ``verbose=True`` in several places since this is the default.

*  Mark the container run during initialize for removal during cleanup.

Signed-off-by: Chris Evich <cevich@redhat.com>