* Run snapshot testing against all demos
* Split demo tests
* ignore coverage folder
* Upgrade antd-demo-jest
* enable cache
* intergate with coveralls.io
* Add node test
* Set worker to 2
https://github.com/facebook/jest/issues/1742
* config coverage
* Set default supportServerRender to true
* feat: remove Table columns paging, close: #2883
* css: add style for table multi-header
* feat: multi-header supports fitler & sorter and so on
* feat: multi-heaader works with Table[scroll.y]
* feat: multi-header should works with Table[scroll.x]
* style: update code style to please lint