chore(package): update grunt-contrib-uglify to version 3.3.0 (#481)

package.json

@@ -44,7 +44,7 @@
     "grunt-contrib-clean": "1.1.x",
     "grunt-contrib-concat": "1.0.x",
     "grunt-contrib-jshint": "1.1.x",
-    "grunt-contrib-uglify": "3.2.x",
+    "grunt-contrib-uglify": "~3.3.0",
     "grunt-conventional-changelog": "6.1.x",
     "grunt-conventional-github-releaser": "1.0.x",
     "grunt-endline": "0.6.x",