fix assetsDir path
fix assetsDir path

camsong/istanbul-flow,gotwarlost/istanbul,ambitioninc/babel-istanbul,ambitioninc/babel-istanbul,omsmith/istanbul,adamjmcgrath/istanbul,adamjmcgrath/istanbul,camsong/istanbul-flow,gotwarlost/istanbul,omsmith/istanbul,ambitioninc/babel-istanbul,gotwarlost/istanbul,omsmith/istanbul,camsong/istanbul-flow,adamjmcgrath/istanbul