Add .editorconfig
Add composer.{json,lock}
Use follow PSR-4 syntax for namespacing
Add ST2 project file
Add phpunit configuration and bootstrap files
Add a basic TestCase to extend from
Fix PSR-4 compatible prefix in composer.json
Add RequestData value object with accompanying tests
Upgrade PHP requirement to 5.5 because of json_last_error_msg
Add a helper class for processing the API response
Use the supplied $response instead of the failed decoded json object

for the InvalidArgumentException message
Remove obsolete TODOs in Response
Expose a static factory function for classes implementing the ResponseInterface
Remove uncessary static ResponseInterface factory function

By simply allowing an empty instantation the object can be passed to
the ReCaptcha object.
Update Response unit tests - check object equality in Response::verify()
Fix interface function phpdoc
Add main business logic
Add recaptcha verification URL as a fallback default to ReCaptcha::processRequest