Ratchet basic chat application giving error "Failed opening required"

I'm trying out the Ratchet library to use WebSockets located at http://socketo.me/ but am experiencing some problems when running the server script from the command line in Ubuntu.

After successfully installing composer and Ratchet I'm following the tutorial for a basic chat application at http://socketo.me/docs/hello-world and I'm at the Running It step. My file structure, with websockets being my project folder, is:

kingsconflict
   websockets
      chat.php
      chat-server.php
      composer.json
      vendor
         autoload.php
         (dependecies included by composer for Ratchet)

The error I get when typing "sudo php chat-server.php" is "PHP Fatal error: require(): Failed opening required '/var/www/kingsconflict/vendor/autoload.php' (include_path='.:/usr/share/php:/usr/share/pear') in /var/www/kingsconflict/websockets/chat-server.php on line 5". It seems like it's trying to open /var/www/kingsconflict/vendor/autoload.php but the actual path is /var/www/kingsconflict/websockets/vendor/autoload.php, and I'm not sure why it's doing this.

chat-server.php

<?php
use Ratchet\Server\IoServer;
use MyApp\Chat;

    require dirname(__DIR__) . '/vendor/autoload.php';    // Error here

    $server = IoServer::factory(
        new Chat()
      , 8080
    );

    $server->run();

I tried subbing the errored line with the line below, and I stop getting the error but I get a new error "PHP Fatal error: Class 'MyApp\Chat' not found" which leads me to believe this fix isn't right.

require ('./vendor/autoload.php');

The code for the other files are the same as shown in the Ratchet tutorial, but just in case I'll post them below

chat.php

<?php
namespace MyApp;
use Ratchet\Mess