changed syntax for validation

Changed the syntax for the validation to be more aligned to the proposed way of implementing custom validations in the docs: https://laravel.com/docs/5.7/validation#custom-validation-rules

app/Http/Controllers/Auth/RegisterController.php

@@ -49,9 +49,9 @@ class RegisterController extends Controller
     protected function validator(array $data)
     {
         return Validator::make($data, [
-            'name' => 'required|string|max:255',
-            'email' => 'required|string|email|max:255|unique:users',
-            'password' => 'required|string|min:6|confirmed',
+            'name' => ['required', 'string', 'max:255'],
+            'email' => ['required', 'string', 'email', 'max:255', 'unique:users'],
+            'password' => ['required', 'string', 'min:6', 'confirmed'],
         ]);
     }