Update to React 0.14

The big change for this release was updating React to 0.14. Thanks to @patrykkopycinski for his PR!

We're still on the 0.13 series of React Router as their recent 1.0 release will require internal updates to Gatsby. Follow along at #32 if interested.

gatsby serve now gatsby develop

Serve implied Gatsby was just serving up files. Develop conveys the idea better that you're starting up a full-fledged development server with the intent to start developing.

Can now do webpack requires in your html.jsx

Previously you couldn't do webpack requires in your html component as the development server was requiring the module in node context. But with the help of @petehunt's webpack-require project, you can now require css or anything else you'd like in your html.jsx.

Improved support for prefixing site links e.g. when building for Github Pages.

See the documentation that's been added to the README.

How to upgrade

You'll need to update React in your project to React 0.14 as well as upgrade any React components that relied on older React APIs. Make sure to not install the latest react-router.