public function store(Request $request)
 {
     $input['from_user'] = $request->user() - id;
     $input['on_post'] = $request->input('on_post');
     $input['body'] = $request->input('body');
     $slug = $request->input('slug');
     Comments::create($input);
     return redirect($slug)->with('message', 'Comment published');
 }