### changes
#### remove trailing spaces
When I was using example I noticed trailing spaces.
So, this PR removes the trailing spaces of json file, README, and others.
`examples/with-jest-typescript/src/modules/cars/Overview.tsx` also has it, but this time it did not change as tslint error occurs at commit.
Fixes#5347
The main issue is that we were waiting only 1 level of dynamic imports, so the dynamic imports nested inside other dynamic import files were not awaited. This would cause either a flash of loading states or you wouldn't see the loading state (because of preload) but it would then show a hydration warning in development.
Thanks to @arthens for providing the reproduction that I modelled the tests after.
**What's this PR?**
Based on the feedback on [this PR](https://github.com/zeit/next.js/pull/5722) @timneutkens asked me to create a test for `ssr: true`
**What's it do?**
- adds a test for setting `ssr: true` - /basic
- adds a test for setting `ssr: true` - /production
* Add failing tests
* Upgrade wd module
* Pass dynamic import webpack ids to the client side
* Pass through webpack ids to initalializer and only use those
* Compile dynamic(import()) to dynamic(() => import())
* Default dynamicIds
* Use forked hard-source-plugin
* Possibly fix test
* Make tests fail less intermittently
* Temporarily disable hard-source in production
* Make sure dynamic import chunks are unique
* Disable hard-source
* Log html if error is thrown
* Fix test
Fixes#5038
The problem with `constructor` is that it doesn't have `context` yet when being called. It's also considered unsafe to add a side-effect on constructor except when server-rendering
* Layout ground works for next/async
* Implement the Dynamic Bundle feature.
* Add some test cases.
* Update README.
* Implement props aware dynamic bundle API.
* Update tests and README.
* Add a test case for React Context support.
* Always check with the fs when gettings chunks.
* Add a new set of test cases for dynamic imports in dev.
* Add dynamic import test cases for production.
* Add availableChunks support for static exports.
