/**
  * Shows an article by it's ID.
  *
  * @return Response
  */
 public function getArticle($alias)
 {
     $article = Article::findByAlias($alias);
     $article = $article->first();
     if ($article === null) {
         throw new NotFoundHttpException();
     }
     $data = ['article' => $article];
     return view('layouts.frontend.article', $data);
 }