Enable CSS sourcemaps in production (facebook#2168)

gaearon · romaindso · commit cc561bf1316f · 2017-07-10T15:27:07.000+02:00
diff --git a/packages/react-scripts/config/webpack.config.prod.js b/packages/react-scripts/config/webpack.config.prod.js
@@ -194,6 +194,7 @@ module.exports = {
                   options: {
                     importLoaders: 1,
                     minimize: true,
+                    sourceMap: true,
                   },
                 },
                 {
