Releasing 0.5.1.
Releasing 0.5.1.

Includes fixes for the following issues:
* #33: Update requests_oauthlib from 0.5.0 -> 0.6.1
* #34: Add LICENSE
* #35: Add supported versions of python
* #38: Fix broken tests in Python 2.7 due to class decorating with
  responses.activate.

Asana/python-asana,asana/python-asana,asana/python-asana