feat(Subscription): add changeDestination update action

Closes #437

Author: jenschude

src/Core/Builder/Update/SubscriptionsActionBuilder.php

@@ -4,6 +4,7 @@
 
 use Commercetools\Core\Error\InvalidArgumentException;
 use Commercetools\Core\Request\AbstractAction;
+use Commercetools\Core\Request\Subscriptions\Command\SubscriptionChangeDestinationAction;
 use Commercetools\Core\Request\Subscriptions\Command\SubscriptionSetChangesAction;
 use Commercetools\Core\Request\Subscriptions\Command\SubscriptionSetKeyAction;
 use Commercetools\Core\Request\Subscriptions\Command\SubscriptionSetMessagesAction;
@@ -12,6 +13,17 @@ class SubscriptionsActionBuilder
 {
     private $actions = [];
 
+    /**
+     * @link https://docs.commercetools.com/http-api-projects-subscriptions.html#change-destination
+     * @param SubscriptionChangeDestinationAction|callable $action
+     * @return $this
+     */
+    public function changeDestination($action = null)
+    {
+        $this->addAction($this->resolveAction(SubscriptionChangeDestinationAction::class, $action));
+        return $this;
+    }
+
     /**
      * @link https://docs.commercetools.com/http-api-projects-subscriptions.html#set-changes
      * @param SubscriptionSetChangesAction|callable $action

src/Core/Request/Subscriptions/Command/SubscriptionChangeDestinationAction.php

@@ -0,0 +1,38 @@
+<?php
+/**
+ */
+
+namespace Commercetools\Core\Request\Subscriptions\Command;
+
+use Commercetools\Core\Model\Common\Context;
+use Commercetools\Core\Model\Extension\Destination;
+use Commercetools\Core\Request\AbstractAction;
+
+/**
+ * @package Commercetools\Core\Request\Subscriptions\Command
+ * @link https://docs.commercetools.com/http-api-projects-subscriptions.html#change-destination
+ * @method string getAction()
+ * @method SubscriptionChangeDestinationAction setAction(string $action = null)
+ * @method Destination getDestination()
+ * @method SubscriptionChangeDestinationAction setDestination(Destination $destination = null)
+ */
+class SubscriptionChangeDestinationAction extends AbstractAction
+{
+    public function fieldDefinitions()
+    {
+        return [
+            'action' => [static::TYPE => 'string'],
+            'destination' => [static::TYPE => Destination::class],
+        ];
+    }
+
+    /**
+     * @param array $data
+     * @param Context|callable $context
+     */
+    public function __construct(array $data = [], $context = null)
+    {
+        parent::__construct($data, $context);
+        $this->setAction('changeDestination');
+    }
+}