Add an ext/hash compatibility layer (just hash_pbkdf2(), for now)
diff --git a/tests/Bootstrap.php b/tests/Bootstrap.php
index 439c7fd..5441f71 100644
--- a/tests/Bootstrap.php
+++ b/tests/Bootstrap.php
@@ -64,6 +64,7 @@
 }
 
 include_once SYSTEM_PATH.'core/compat/mbstring.php';
+include_once SYSTEM_PATH.'core/compat/hash.php';
 include_once SYSTEM_PATH.'core/compat/password.php';
 
 include_once $dir.'/mocks/autoloader.php';