Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in /home/sta963/public_html/back-end/vendor/laravel/framework/src/Illuminate/Foundation/Testing/TestCase.php:18 Stack trace: #0 {main} thrown in /home/sta963/public_html/back-end/vendor/laravel/framework/src/Illuminate/Foundation/Testing/TestCase.php on line 18