Add Server Class, known_inboxes method

includes/class-server.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace Activitypub;
+
+/**
+ * ActivityPub Server Class
+ *
+ * @author Django Doucet
+ */
+class Server {
+
+	private static function known_inboxes () {
+		$authors = get_users( array(
+			'capability' => 'publish_posts'
+		) );
+		$follower_inboxes_all = [];
+		foreach ( $authors as $user ) {
+			$follower_inboxes = Followers::get_inboxes( $user->ID );
+			$follower_inboxes_all = array_merge( $follower_inboxes, $follower_inboxes_all );
+		}
+		return array_unique( array_filter( $follower_inboxes_all ) );
+	}
+
+}