* Added travis file

* Dropping node 5

* Added os field as well

* Removed os, fails on both osx and linux

* Adding ava and sockjs-client as devDeps

* Shouldn't need ava 🤔

* Moved sockjs-client to dependency

This reverts commit f4ae99fc.

* pass pathname and query to getInitialProps on both server and client

* README: describe about the contet object of getInitialProps

* add detach-plugin

* detach-plugin: remove unused property

* watch-pages-plugin: replace _error.js when user defined one was added/removed

* dynamic-entry-plugin: delete cache

* fix HMR settings for _error.js

* render: pass error only on dev

* hot-reload: enable to hot-reload error page

* server: check if /_error has compilation errors

* webapck-dev-client: fix reloading /_error

* next init: Create supplied directory if it does not exist.

* next init: use mkdirp to init into nested dirs.

Picked mkdirp-then out of many alternatives. Same author & similar
dependencies to mz.

Now next init a/b/c works.

Related https://github.com/zeit/next.js/pull/136#discussion_r85543040

* Enhance system font stack on _error.js

`-apple-system` = SF on Safari (macOS/iOS)
`BlinkMacSystemFont` = SF on Chrome (macOS)
`Roboto` for Android
`Segoe UI` for Windows
`Fira Sans` for Firefox OS
`Avenir` for pre-SF macOS
`Helvetica Neue, Lucida Grande` for older macOS

* Enhance system font stacks on _error-debug.js

Updates fonts to use better quality system fonts where commonly available

Should only exit `0` if the command was successful. The command refusing to execute should be considered a failure.

Also, this condition can be detected synchronously, no need to wait on the async existence check.

* Expose next/css, next/link, and next/head.

This allows test runners like Jest and ESLint's file resolver to
be able to find exported modules within `next`.

Fixes #113

* Removed semicolons for linting and expose modules.

* Add license MIT

* Fix typo

* Remove extension LICENSE

* Change copyright to Zeit, Inc.

* Remove section license in README file

* Update README.md

The CSS rule on the error page doesn't work and the text on the page isn't rendered in SF UI Text. If we want to use SF on the error page, then, at least in Safari, we can use `-apply-system` as the font family.

I also added a fallback to sans-serif, just to be explicit.

* head-manager: batch update

* side-effect: remove redundant rendering cycle checks