Fix typo

Author: joecampo

config/config.php

@@ -1,7 +1,7 @@
 <?php
 
 return [
-    'apiURL'    => env('SS_URL', 'https://ssapi.shipstation.comm'),
+    'apiURL'    => env('SS_URL', 'https://ssapi.shipstation.com'),
     'apiKey'    => env('SS_KEY', ''),
     'apiSecret' => env('SS_SECRET', ''),
 ];