Fix default endpoint.

Author: mfauveau

src/Message/AbstractRequest.php

@@ -6,7 +6,7 @@
 */
 abstract class AbstractRequest extends \Omnipay\Common\Message\AbstractRequest
 {
-    protected $endpoint = 'https://gateway.perpetualpayments.com/api/transact.php';
+    protected $endpoint = 'https://secure.nmi.com/api/transact.php';
 
     public function getUsername()
     {
@@ -153,6 +153,11 @@ public function sendData($data)
         return $this->response = new DirectPostResponse($this, $httpResponse->getBody());
     }
 
+    public function setEndpoint($value)
+    {
+        return $this->setParameter('endpoint', $value);
+    }
+
     public function getEndpoint()
     {
         return $this->endpoint;