Fix a bad tearDown method in test_quantumv2.py.

Cleanup code runs in LIFO order, so this was calling the mox methods
in the wrong order. Secondly the whole point of addCleanup is to
register code to run as soon as it is known that it should run, vs
tearDown which only runs if setUp succeeds, and doesn't know what
other code completed.

Change-Id: Iff3b91e9d43cc58b667b32cacc4b97b6e0e1f298
Merge "Fix a bad tearDown method in test_quantumv2.py."