Update app config, add Str alias

config/app.php

@@ -210,6 +210,7 @@ return [
         'URL'          => Illuminate\Support\Facades\URL::class,
         'Validator'    => Illuminate\Support\Facades\Validator::class,
         'View'         => Illuminate\Support\Facades\View::class,
+        'Str'         => Illuminate\Support\Str::class,
 
         'PrettyNumber' => App\Util\Lexer\PrettyNumber::class,
         'Purify'       => Stevebauman\Purify\Facades\Purify::class,