Add outline HttpClient class

src/Client/HttpClient.php

@@ -0,0 +1,24 @@
+<?php
+namespace ActivityPub\Client;
+
+use Symfony\Component\HttpFoundation\Request;
+
+/**
+ * The HttpClient provides methods to send HTTP requests to other servers
+ */
+class HttpClient
+{
+    /**
+     * Sends the $request
+     *
+     * @param Request $request The request
+     * @return Response The HTTP response
+     */
+    public function send( Request $request )
+    {
+        // TODO implement me
+        // Use symfony\psr-http-message-bridge to convert the Request to a
+        // PSR-7 request which Guzzle understands
+    }
+}
+?>