v7 release

[johno]

Bumping dependencies like styled-components will essentially be a breaking change, so I'm looking to aggregate other changes we can bring into a major release.

• webpack-dev-server Fix: switch over to webpack-dev-server #105
• Bump dependencies
  • styled-components Bump styled-components to v4 #109
  • emotion
  • react
• Move to @reach/router
• Ability to opt out of all styling
• Move all the providers to the layout

Possibilities

• Typescript support
• Linter/prettier

[tuoxiansp]

hope can switch to other versions of react, so that I can use Hooks API with x0 playground :)