Add after_creating to factory class

[josephmancuso]

Here is an example in PHP:

$factory->afterCreating(Sku::class, function ($sku, $faker) {
    $skuUomId = factory(SkuUom::class)->create([
        "sku_id" => $sku->sku_id,
        "quantity" => 1,
        "gtin_prefix" => '00',
        "used_for_selling" => 1,
        "used_for_purchasing" => 1,
        "used_for_picking" => 1,
        "can_be_packaged" => 1,
    ])->sku_uom_id;

    $sku->base_uom_id = $skuUomId;
    $sku->default_sales_uom_id = $skuUomId;
    $sku->default_purchasing_uom_id = $skuUomId;
    $sku->default_picking_uom_id = $skuUomId;
    $sku->save();
});

After the factory is created, if there is an after_creating registered for that model it should pass the result and a faker instance to this callable