The fix is to add a heartbeat less than 5 secs.

* Fix test failures due to styled-jsx change.

* Update styled-jsx to the latest.

* Add a configuration parameter to custom server startup

* Adding related documentation

* Do not access filesystem if configuration is supplied

* Make the configuration log clearer

* Make the conf default value to `null`

Fixed broken readme link and make it short by removing unnecessary invitation.

* Fixed all unsupported style properties

Fix https://github.com/zeit/next.js/pull/1817#issuecomment-299738931

* add antd-mobile example

* update antd-mobile@1.1.2

remove unsupported page

add menu to trick page

* Add ant design example

* Reduce bundle size by importing modularized antd

* lock react version for warning

* add postcss after sass compilation

* Fix indent

* Fixed mixed tab indent with spaces

Fixes #1191

Just after a 404 page, if we created a page with
no default exports. It'll throw an error.
And it'll crash internal webpack state.
So, once we have it we need to do a hard reload to recover it.

* Never cache assets and HTML in the dev mode.

* Move etags test to the production.

Now it won't work in dev because of no-cache settings.

* Check if _document.js returns a react element before using

* Use capital letter R in 'React'

* Allow to test on Node.js v4

* Add appveyor.yml file

* Update appveyor badge to master branch.

* Many improvements to the Apollo examples

* Use static properties