Google's simple reCAPTCHA client, this client is just a refactored version of Google's PHP reCAPTCHA lib.
use Nebiros\GoogleSimpleRecaptchaClient\Client as RecaptchaClient;
$recaptchaClient = new RecaptchaClient($recaptchaSecret);
$resp = $recaptchaClient->verifyResponse(
$_SERVER["REMOTE_ADDR"],
$_POST["g-recaptcha-response"]
);