The python-glanceclient pythonic API shouldn't break until v2 is
released, so let's allow anything up to that known point.
Alters the way test exceptions are constructed so that we're
not dependent on the internals of how 3rd party libraries
handle their exceptions while still being able to use them
for real testing in Horizon.
Fixes bug 1035511
Change-Id: I9a4379a19d5d6dee9d2349a73d9321def45ad78d
caf166eacb