Fatal error: Class 'Graze\GuzzleHttp\JsonRpc\Test\FunctionalTestCase' not found

[sunujacob]

I am trying to use this plugin in my php class on amazon server. I required all files.

function _require_all($dir)
{
    // require all php files
    $scan = glob("$dir/*");
    foreach ($scan as $path) {
        if (preg_match('/\.php$/', $path)) {
            require_once $path;
        } elseif (is_dir($path)) {
            _require_all($path);
        }
    }
}

_require_all("monero/monero-php-master/vendor/");
require_once('monero/monero-php-master/vendor/autoload.php');
require_once('monero/monero-php-master/src/Wallet.php');

I get below error. Please HELP

Fatal error: Class 'Graze\GuzzleHttp\JsonRpc\Test\FunctionalTestCase' not found in /var/www/html/plugins/monero/monero-php-master/vendor/graze/guzzle-jsonrpc/test/functional/BatchFunctionalTest.php on line 17