Merge pull request #295 from mercadopago/feature/add-response-external-reference-id

[Feature] add external-reference in response

Author: andreagostinho-meli

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

@@ -8,4 +8,13 @@ public class PaymentData {
 
   /** PaymentRules. */
   private PaymentRules rules;
+
+  /** Reference Id. */
+  private String referenceId;
+
+  /** External Reference Id. */
+  private String externalReferenceId;
+
+  /** External Resource Url. */
+  private String externalResourceUrl;
 }