* fixed package dependencies.

package.json

@@ -29,6 +29,7 @@
     "grunt-contrib-uglify": "~0.2.7",
     "grunt-contrib-cssmin": "~0.7.0",
     "grunt-contrib-clean": "~0.5.0",
+    "grunt-contrib-watch": "~0.5.3",
     "grunt-csscomb": "~2.0.1",
     "grunt-banner": "~0.2.0",
     "load-grunt-tasks": "~0.2.1"