The python environment variable we set for those python3 related tests
like test_libapparmor_testsuite3() and test_utils_testsuite3() should
be cleared after test if they're not set before.
Otherwise this will make test_utils_testsuite() to be tested with
python3 if we're trying to run the whole test-apparmor.py suite
directly.
test-apparmor.py: make it possible to run tests one-by-one
Don't explictly add test classes into unittest.TestSuite() but just
use unittest.main() instead. So that we will be able to run single
test with:
./test-apparmor.py -v ApparmorTest.test_aa_status
The whole suite can still be triggered with:
./test-apparmor.py -v
See --help for more information for unittests.
And skip test with unittest.skipUnless.
Without the need to run through everything, this change will make it
easier to debug a single failure.
