Refactoring and formatting tweaks for great justice.
Fixing failing tests for Simple adapter due to \r characters.
Fixing tests failing in browser due to HTTP_HOST.
Refactoring to adhere to li3 coding standards (li3_quality).
Adding travis config.
Fixing travis configuration.
Refactoring Simple adapter to have the internal function `mail` as a dependency to ease testing.
Refactoring to adhere to li3 coding standards (li3_quality).
Recatoring Simple adapter to be more reusable.
Adding the Mailgun adapter.

Fixes #5.
Original authors: Mitch Pirtle (https://github.com/spacemonkey) and Francesco Cogoni (https://github.com/fcogoni)
Refactoring to adhere to li3 coding standards (li3_quality).
Switching to official li3_quality on travis.