adding tox support, and support for python setup.py test, and tests for ...

[jtushman]

...pypy

[jtushman]

This is a known failing test. For you have some issues with pypy. Feel free to comment out of your t.travis.yml if you do not want to support pypy

[EvaSDK]

Imho using nose over default unittest module is just for cosmetics and should be left to travis/tox configuration, not mandatory for running tests that do run fine without it.