Fix version of PHPUnit configuration file schema

Author: Jamie Snape

phpunit.xml.dist

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:noNamespaceSchemaLocation="http://schema.phpunit.de/4.3/phpunit.xsd"
+         xsi:noNamespaceSchemaLocation="http://schema.phpunit.de/4.4/phpunit.xsd"
          bootstrap="tests/TestsBootstrap.php"
          colors="true">
     <testsuites>