Update grunt-contrib-nodeunit to version 2.0.0

Closes js-cookiegh-443

Author: greenkeeper[bot]

package.json

@@ -36,7 +36,7 @@
     "grunt-compare-size": "0.4.2",
     "grunt-contrib-connect": "1.0.2",
     "grunt-contrib-jshint": "1.1.0",
-    "grunt-contrib-nodeunit": "1.0.0",
+    "grunt-contrib-nodeunit": "2.0.0",
     "grunt-contrib-qunit": "2.0.0",
     "grunt-contrib-uglify": "2.3.0",
     "grunt-contrib-watch": "1.1.0",