travis-ci not correctly report test result

[reverbc]

Travis-CI is saying at the moment, but actually it's not: https://travis-ci.org/stchris/untangle/jobs/255641301

There's two issues with current setting:

1. the tests were running in ALL the python environments (from py26 to pypy) with tox in ALL travis-ci platform (should be one python environment with one platform)
2. in setup.py the tests were executed with the following commands:

   os.system('tox')
   sys.exit()

   and the second line will make the test error code not being reported to invoker (in this case, the travis-ci).

There will be two PRs to resolve the above issues: the first one will be fixing all current unit test errors (one of them caused by me - sorry!), and the second one will fix the CI configuration. Please consider accept and merge them in order to prevent travis-ci disallow PR due to test failure. Thanks.

[stchris]

Closed after #82