Add test case for --no-fake switch
Add test case for --no-fake switch

This test case is not a proper test for the fix, however.  To actually test
the fix, we would have to use a shell command instead of the internal API,
which would necessitate converting TransactionTestCase to TestCase, which
would hose many of the test methods in BackupTestCase.

murphyke/avocado,murphyke/avocado,murphyke/avocado,murphyke/avocado