Added Update Method in Payment

- Payment allows update calls with patch requests
- Samples to demonstrate its abilities

sample/index.php

@@ -270,6 +270,17 @@ if (PHP_SAPI == 'cli') {
 
                 </div>
             </li>
+            <li class="list-group-item">
+                <div class="row">
+                    <div class="col-md-8"><h5>Update payment details</h5></div>
+                    <div class="col-md-4">
+                        <a href="payments/UpdatePayment.php" class="btn btn-primary pull-left execute"> Try It <i
+                                class="fa fa-play-circle-o"></i></a>
+                        <a href="doc/payments/UpdatePayment.html" class="btn btn-default pull-right">Source <i
+                                class="fa fa-file-code-o"></i></a>
+                    </div>
+                </div>
+            </li>
             <li class="list-group-item">
                 <div class="row">
                     <div class="col-md-8"><h5>Get payment details</h5></div>