Facade 'Icon' => Bootstrapper\Facades\Icon::class doesn't get glyphicon in Bootstrap 4

I've noticed that glyphicon was dropped (see http://v4-alpha.getbootstrap.com/migration/) after updating my app to Bootstrap 4.

How can I change automatic generation of code to another library (like open-iconic). **Today, the automatic generated code like**:
`<span class='glyphicon glyphicon-floppy-disk'></span>`
**And I need to change it to:**
`<span class='oi oi-floppy-disk'></span>`