Added base plugin, in preperation for the API

src/Message/AbstractResponse.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace Omnipay\Inforbank\Message;
+
+use Omnipay\Common\Message\AbstractResponse as BaseAbstractResponse;
+use Omnipay\Common\Message\RequestInterface;
+
+abstract class AbstractResponse extends BaseAbstractResponse
+{
+    protected $error;
+
+    public function __construct(RequestInterface $request, $data)
+    {
+        parent::__construct($request, $data);
+        if (!$this->data->success) {
+            $this->error = (string) $this->data->error;
+        }
+    }
+}