provide a valid utf8 multibyte test for nova images

this only works for json because getting our xml client to be
fully utf8 compliant would be *a ton* of work.

Change-Id: I5e2f05274aaa6a2eb97b6206240ffd44e9f12526
Related-Bug: #1006725
Merge "provide a valid utf8 multibyte test for nova images"