Chain values method in map function

[xcaptain]

refer to my pull request in ErickTamayo/laravel-scout-elastic#66

collect([0 => ['id' => 1], 1 => ['id' => 2], 2 => null, 3 => ['id' => 3]])->filter()

would get

collect([0 => ['id' => 1], 1 => ['id' => 2], 3 => ['id' => 3]])

which would make paginate() returned an object rather than list.