update disable-key for validate

README.md

@@ -63,7 +63,7 @@ public function rules()
 For tests
 ---------
 
-Use key ```RECAPTCHA_OFF``` in ```index-test.php``` for disable recaptcha's validate:
+When use ```YII_ENV_TEST``` in ```index-test.php``` then disabled recaptcha's validate:
 ```php
-define('RECAPTCHA_OFF', true);
+defined('YII_ENV') or define('YII_ENV', 'test');
 ```

src/ReCaptcha.php

@@ -55,7 +55,7 @@ public function registerScript($view)
      */
     public function validateValue($value)
     {
-        if (defined('RECAPTCHA_OFF') && RECAPTCHA_OFF) {
+        if (YII_ENV_TEST) {
             return 1;
         }