Add "list Glance API versions" test

Many projects provides multiple API versions and the version
information is very important for users, because users can know
what features are available on clouds. However, Tempest didn't
test the Clance API versions in long-term. So this patch adds
the corresponding test.

Change-Id: Ib85819fb71f0b12b64351b307d83a3beb77d7fad
7 files changed