Extend changes for sync event

Hello!

I'd like to ask you could you please extend changes array for sync events like in the attached event (with additional attributes info) Now it looks like this:

[
   "attached" => [
     0 => 3
   ]
   "detached" => [
     1 => 2
   ]
   "updated" => [
     0 => 1
   ]
 ]

Extend changes array:

[
   "attached" => [
     1 => ['attribute' => '', 'attribute2' => ''], 
     2 => ['attribute' => 'test', 'attribute2' => 'test2']
   ],
   "detached" => [4, 5],
   "updated" => [
     3 => ['attribute' => 'test3', 'attribute2' => 'test4']
   ],
 ]

mikebronner / laravel-pivot-events

Extend changes for sync event #10