Use 'hash'

Author: gedorinku

build/webpack.prod.conf.js

@@ -44,7 +44,7 @@ const webpackConfig = merge(baseWebpackConfig, {
     }),
     // extract css into its own file
     new ExtractTextPlugin({
-      filename: utils.assetsPath('css/[name].[contenthash].css'),
+      filename: utils.assetsPath('css/[name].[hash].css'),
       // Setting the following option to `false` will not extract CSS from codesplit chunks.
       // Their CSS will instead be inserted dynamically with style-loader when the codesplit chunk has been loaded by webpack.
       // It's currently set to `true` because we are seeing that sourcemaps are included in the codesplit bundle as well when it's `false`,