public function create($parent_slug = null)
 {
     /**
      * @todo Limit this list to the categories this user can manage
      */
     $categories = Category::get()->lists('name', 'id');
     $category = Category::whereSlug($parent_slug)->first();
     $this->authorize('laraboard::board-create', $category);
     $parent_id = null;
     if (!empty($category)) {
         $parent_id = $category->id;
     }
     return view('laraboard::board.create', compact('categories', 'parent_id'));
 }