change default string length

app/Providers/AppServiceProvider.php

@@ -3,6 +3,7 @@
 namespace App\Providers;
 
 use Illuminate\Support\ServiceProvider;
+use Schema;
 
 class AppServiceProvider extends ServiceProvider
 {
@@ -14,6 +15,7 @@ class AppServiceProvider extends ServiceProvider
     public function boot()
     {
         //
+        Schema::defaultStringLength(191);
     }
 
     /**