remove coffee

Author: SunLn

package.json

@@ -12,7 +12,6 @@
         "grunt": "~0.4.2",
         "grunt-contrib-jshint": "~0.7.2",
         "grunt-contrib-watch": "~0.5.3",
-        "grunt-contrib-coffee": "~0.10.1",
         "grunt-contrib-uglify": "~0.2.2",
         "grunt-contrib-copy": "~0.5.0"
     }