Updating mailsnake to use requests

This version is using the famous HTTP Python for human beings library https://github.com/kennethreitz/requests

* Moving from urllib2 to requests, turns code neater and shorter
* Refactoring some code
* Adding a basic initial test suite for the library
* Fixing some setup.py flaws, don't forget to add `author_email` to setup.py 

Regards,
Miguel