JPG image optimization not working
https://github.com/gruntjs/grunt-contrib-imagemin/issues/16node
npm uninstall grunt-contrib-imagemin && npm install grunt-contrib-imagemin
node-jpegtran-bin
https://github.com/yeoman/node-jpegtran-bingit
npm install --save jpegtran-bin
換個路徑好了,把路徑下的其餘圖片刪掉也好了github