Added a blank test and configured phpunit
updated dependencies
Added the first basic implementation:
* the HTTP client tied to emailvision extends the Guzzle client
* you need to pass an array with the emailvision's configuration
* a specific exception is thrown if you don't pass all the required parameters
* added the actual method to send the request to emailvision (sendEmail)
Added more informations in the README
Merge branch 'develop'