Unicode regression

When feeding unicode strings into `urlencode`, [hell breaks loose](http://stackoverflow.com/questions/6480723/urllib-urlencode-doesnt-like-unicode-values-how-about-this-workaround). This is a regression test, mocking `urllib2.urlopen` and a patch fixing `urlencode()`.

As a bonus, I've added [coveralls](https://coveralls.io/) support for the Travis tests, this should make it harder for untested code (which was the case) to go unnoticed. Enabling coveralls is as easy as enabling Travis - however if you don't want this I'm happy to remove the patch from the Pull req.

As a bonus, I've also added a generic `make_request` test (for `json=Fals`), mostly to show the way forward in extended (Mocked) testing.