Added 4.2 version support

Author: stefanak-michal

src/protocol/V4_2.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace Bolt\protocol;
+
+/**
+ * Class Protocol version 4.2
+ *
+ * @author Michal Stefanak
+ * @link https://github.com/stefanak-michal/Bolt
+ * @package Bolt\protocol
+ */
+class V4_2 extends V4_1
+{
+
+}