### 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.
* 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.
