Umi: Use webpack@4

[sorrycc]

• https://www.codementor.io/valentino/webpack-4-tutorial-all-you-need-to-know-from-0-conf-to-production-mode-g4lpnr47v
• https://medium.com/webpack/webpack-4-beta-try-it-today-6b1d27d7d7e2

[minwe]

建议 Webpack 输出更多的日志，这样感觉起来会快一点，现在构建时就是一个静止的提示，看着比较沉闷，也会觉得比较满。

看来 Gmail 加了个进度条，让用户感觉快了，还真是不无道理。

[minwe]

在构建速度上，Roadhog（Weback 3）并没有比 atool-build（Webpack 1） 快，不知道 Webpack 4 会不会有质的提升，期待一下。

[sorrycc]

Wait for https://github.com/facebook/create-react-app/pull/4077

[superlbr]

andriijas say 'There is no need to use the AutoDllPlugin'.
Is that means there's no need umi-plugin-dll if use webpack@4?

[sorrycc]

Related issue, with webpack@4, we could reduce the bundle size.

• https://github.com/ReactTraining/react-router/pull/6082
• https://webpack.js.org/guides/tree-shaking/#mark-the-file-as-side-effect-free

[wadezhan]

wait for webpack@4 to use SplitChunksPlugin

[sorrycc]

And wait for this, https://github.com/webpack/webpack/issues/6767#issuecomment-374248413

[mizi-lin]

是否能出个 beta 版 使用 webpack4 呢··

[superlbr]

webpack/webpack#6767 (comment) is too open to locate
how about wait for https://github.com/facebook/create-react-app/issues/4492