* Removal of oauth2 lib, `requests` has fully taken over. :)
* FIXED: Obtaining auth url with specified callback was broke..
wouldn't give you auth url if you specified a callback url
* Updated requests to pass the headers that are passed in the init, so
User-Agent is once again `Twython Python Twitter Library v2.1.0`
👍 :)
* Catching exception when Stream API doesn't return valid JSON to parse
* Removed `DELETE` method. As of the Spring 2012 clean up, Twitter no
longer supports this method
* Updated `post` internal func to take files as kwarg
* `params - params or {}` only needs to be done in `_request`, just a
lot of redundant code on my part, sorry ;P
* Removed `bulkUserLookup`, there is no need for this to be a special
case, anyone can pass a string of username or user ids and chances are
if they're reading the docs and using this library they'll understand
how to use `lookupUser()` in `twitter_endpoints.py` passing params
provided in the Twitter docs
* Changed internal `oauth_secret` variable to be more consistent with
the keyword arg in the init `oauth_token_secret`
