Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in /var/www/usonboard.com/vendor/guzzlehttp/promises/tests/UtilsTest.php:17 Stack trace: #0 {main} thrown in /var/www/usonboard.com/vendor/guzzlehttp/promises/tests/UtilsTest.php on line 17