title: Slim 3 - Error is not shown
body: <p>I am trying to use <a href="https://github.com/zeuxisoo/php-slim-whoops" rel="nofollow noreferrer">zeuxisoo/slim-whoops</a>  to show errors, but for some reason I am only getting white screen without any message show. This is the code I am using (I don't know if it does matter, I am using quick PHP host (php -S localhost:8000):</p>
  
  <pre><code>require __DIR__ . '/../vendor/autoload.php';
  
  $app = new Slim\App([
  
      'settings' =&gt; [
          'displayErrorDetails' =&gt; true,
          'debug'               =&gt; true,
          'whoops.editor'       =&gt; 'sublime',
      ]
  
  ]);
  
  $app-&gt;add(new \Zeuxisoo\Whoops\Provider\Slim\WhoopsMiddleware);
  </code></pre>