Add missing import

Author: andjsch

src/ServiceProvider.php

@@ -4,6 +4,7 @@
 
 use Illuminate\Support\Facades\File;
 use Illuminate\Support\Str;
+use Statamic\Facades\Icon; 
 use Statamic\Fieldtypes\Sets;
 use Statamic\Providers\AddonServiceProvider;