Removed logic in refundTransaction that passes

 only the last 4 digits of credit card number. This makes it possible to do ad-hoc refunds that aren't tied to an existing transaction.

Author: richardgirges

lib/AuthorizeNetGateway.js

@@ -313,7 +313,6 @@ AuthorizeNetGateway.prototype.refundTransaction = function refundTransaction (tr
 
 
   return fullOptions.then(function (fullOpt) {
-    fullOpt.creditCardNumber = fullOpt.creditCardNumber.substr(-4);
 
     return this.sendTransactionRequest({
       transactionType: 'refundTransaction',