Remove not needed tests/bootstrap.php

Signed-off-by: Michal Čihař <michal@cihar.com>

Author: nijel

phpunit.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <phpunit backupGlobals="false"
          backupStaticAttributes="false"
-         bootstrap="tests/bootstrap.php"
+         bootstrap="vendor/autoload.php"
          colors="true"
          convertErrorsToExceptions="true"
          convertNoticesToExceptions="true"