Remove a package from laravel

I installed this Cartalyst Stripe package for laravel which was nothing but trouble for me.. I just couldn't get it working and now I decided to remove it completely. So, I remove the line that requires this package in composer.json. I removed the line from confing/app.php from the providers & aliases array. I also removed all references of that Cartalyst package from my code.. Somehow, after I run composer update I still get this error..

  [Symfony\Component\Debug\Exception\FatalThrowableError]
  Class 'Cartalyst\Stripe\Laravel\StripeServiceProvider' not found


Script php artisan optimize handling the post-update-cmd event returned with error code 1

What am I missing here?

via Chebli Mohamed