Add test for Nova list-versions API

This commit adds a test that does a GET on the raw endpoint to
ensure that the nova version GET does the right thing.

Co-Authored-By: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>

Related-Bug: #1491579
Change-Id: I5ee09891cd1b62a87d25284be961c2027cdbd82a
5 files changed