Composer suggestion includes deprecated package

[cloudchristoph]

Just a really small thing i've noticed in your composer.json:

kriswallsmith/assetic is not maintained anymore. The new package should be assetic/framework from https://github.com/assetic-php/assetic

https://github.com/maximebf/php-debugbar/blob/c2e310320b7751a959f1590bb76530abbcfd2ce6/composer.json#L34

Keep up the great work. It helps alot!