Updated PHPMD version.

composer.json

@@ -35,7 +35,7 @@
         "behat/mink-selenium2-driver": "1.3.0",
         "friendsofphp/php-cs-fixer": "1.11.6",
         "phploc/phploc": "2.0.6",
-        "phpmd/phpmd": "1.5.0",
+        "phpmd/phpmd": "2.4.2",
         "phpunit/phpunit": "4.8.27",
         "sebastian/phpcpd": "2.0.0",
         "squizlabs/php_codesniffer": "2.6.0"