public function POST_write_til(Request $request)
 {
     $this->authorize('til-write');
     $writer_id = Auth::user()->id;
     $cate_title = $request->input('category');
     $cate_title = trim($cate_title);
     $category = TilCategory::where('title', $cate_title)->first();
     if (!$category) {
         $category = TilCategory::create(['title' => $cate_title, 'writer_id' => $writer_id]);
     }
     $request->merge(['category_id' => $category->id, 'writer_id' => $writer_id]);
     TilPost::create($request->all());
     return redirect("members/{$writer_id}/til");
 }