start a restructure

Behavioral/Mediator/Subsystem/Database.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace DesignPatterns\Mediator\Subsystem;
+
+use DesignPatterns\Mediator\Colleague;
+
+/**
+ * Database is a database service
+ */
+class Database extends Colleague
+{
+    /**
+     * @return string
+     */
+    public function getData()
+    {
+        return "World";
+    }
+}