This reverts commit 8c88ec6383. Fix #240
8c88ec6383
* Make SW generation prod-only * Use SpeedMeasurePlugin * Refactor: Symlink directories for dev builds * Lint fix * Remove SpeedMeasurePlugin
* introduce prod/dev build https://webpack.js.org/guides/production/ * use it properly with express https://webpack.js.org/guides/development/#using-webpack-dev-middleware to provide a fast npm start (5 second)