add merchant channel config

helper/refill/policy/mchannel.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace refill;
+
+class mchannel
+{
+    private $mMchidChannels;
+    public function __construct()
+    {
+        $this->load();
+    }
+
+    public function load()
+    {
+
+    }
+}