A exception will now throw when a incorrect email or password is given.
Add unit tests.
Types
Bugfixes

- request.post().raw without stream=True might return nothing (http://docs.python-requests.org/en/latest/user/quickstart/#raw-response-content)
- I forgot to change self.assertEquals(MegaIncorrectPasswordException, …) back to self.assertEquals().
Unit tests improvements

Improve the runtime for unit test for 35 seconds to 13 seconds (for me).
Types...
Merge pull request #3 from Matt3o12/master

Better exception handling.