当前时间

    , 'published_at' => Carbon\Carbon::now()]);
=> <App\Article #0000000059d1c4430000000041be01e5> {
       title: "New Title",
       body: "New body",
       published_at: <Carbon\Carbon #0000000059d1c4420000000041befba5> {
           date: "2015-05-14 14:00:52",
           timezone_type: 3,
           timezone: "UTC"
       },
       updated_at: "2015-05-14 14:00:52",
       created_at: "2015-05-14 14:00:52",
       id: 2
   }