fix(package): update grunt-contrib-uglify to version 3.3.0

Closes #11

Author: greenkeeper[bot]

package.json

@@ -13,7 +13,7 @@
     "grunt-contrib-cssmin": "~2.0.0",
     "grunt-contrib-jst": "~1.0.0",
     "grunt-contrib-less": "1.4.1",
-    "grunt-contrib-uglify": "~2.1.0",
+    "grunt-contrib-uglify": "~3.3.0",
     "grunt-contrib-watch": "~1.0.0",
     "grunt-sails-linker": "~1.0.4",
     "grunt-sync": "~0.6.2",