Add npm sass compiler

package.json

@@ -15,6 +15,7 @@
     "grunt-contrib-cssmin": "^0.12.2",
     "grunt-contrib-jshint": "^0.11.2",
     "grunt-contrib-less": "^0.12.0",
+    "grunt-contrib-sass": "^0.9.2",
     "grunt-contrib-uglify": "^0.7.0",
     "grunt-contrib-watch": "~0.6.1",
     "grunt-cssjanus": "^0.2.4",