yii-grecaptcha usage instructions

1. support pjax usage
2. check source code and google reCaptcha
3. get reCaptcha sitekey and privatekey form reCaptcha admin
4. import GreCaptcha and GreCaptchaValidator
5. use in view

widget('extensions.grecaptcha.GreCaptcha',
		                    array(
							'model'=>$model,
                            'pjax'=>true,
							'siteKey'=>'your site key'
							)
                        );

6. use in model

public $reCaptcha;
public function rules() {
    return array(
	    array(
        'reCaptcha',
        'pathto GreCaptchaValidator',
        'privateKey'=>'your private key',
        'on'=>'your action'
        )
	)
}