Making twython work (again?) in Python 3

* Added a HISTORY.rst to start tracking history of changes

* Updated twitter_endpoints.py to endpoints.py for cleanliness

* Removed twython3k directory, no longer needed

* Added compat.py for compatability with Python 2.6 and greater

* Added some ascii art to __init__.py as well as moved description of
Twython and __author__ to __init__

* Added version.py to store the current Twython version, instead of
repeating it twice -- it also had to go into it's own file because of
dependencies of requests and requests-oauthlib, install would fail
because those libraries weren't installed yet (on fresh install of
Twython)

* Removed find_packages() from setup.py, only one package -- we can
just define it

* added quick publish method for Ryan and I:
python setup.py publish is faster to type and easier to remember than
python setup.py sdist upload

* Removed base_url from endpoints.py because we're just repeating it in
Twython.__init__