test.php

<?php 
  namespace myNamespace;

  ini_set('display_errors',1);
  ini_set('display_startup_errors',1);
  error_reporting(-1);
  echo "hi";
  require_once('vendor/autoload.php');

  \Braintree_Configuration::environment('sandbox');
  \Braintree_Configuration::merchantId('jpqc7f4drntc3z7g');
  \Braintree_Configuration::publicKey('5jhh2342w8mf83pc');
  \Braintree_Configuration::privateKey('private key');


  $clientToken = \Braintree_ClientToken::generate();
  echo $clientToken;