chore(package): update grunt-contrib-jshint to version 2.1.0

Closes #23

Author: greenkeeper[bot]

package.json

@@ -20,7 +20,7 @@
     "grunt-contrib-concat": "^1.0.1",
     "grunt-contrib-connect": "^1.0.2",
     "grunt-contrib-copy": "^1.0.0",
-    "grunt-contrib-jshint": "^1.1.0",
+    "grunt-contrib-jshint": "^2.1.0",
     "grunt-contrib-uglify": "^3.3.0",
     "grunt-contrib-watch": "^1.0.0",
     "grunt-filerev": "^2.3.1",