add more fields

Author: vicorrea25

src/main/java/com/mercadopago/resources/payment/PaymentData.java

@@ -9,6 +9,12 @@ public class PaymentData {
   /** PaymentRules. */
   private PaymentRules rules;
 
+  /** Reference Id. */
+  private String referenceId;
+
   /** External Reference Id. */
   private String externalReferenceId;
+
+  /** External Resource Url. */
+  private String externalResourceUrl;
 }