Fix another typo

phpunit.xml

@@ -1,6 +1,6 @@
 <phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:noNamespaceSchemaLocation="phpunit.xsd"
-         bootstrap="tests/bootstrap.php"
+         bootstrap="test/bootstrap.php"
          verbose="true"
          colors="true">
     <testsuites>