Migrate to react-router v4

[shogowada]

TODOs:

• Summarize breaking changes
• Update documentation

Breaking Changes:

• Drop support for Scala 2.11
  • It was having issue resolving WebBrowser class for no obvious reason.
• When rendering components, use

  <(new MyClassSpec())(/* props */)(/* children */)

  instead of

  (new MyClassSpec())(/* props */)(/* children */)

• Use ^.wrapped to assign custom props and props.wrapped to access them

  object MyComponent {
    case class WrappedProps(message: String)
  }
  class MyComponent extends StatelessReactClassSpec[MyComponent.WrappedProps] {
    override def render(): ReactElement = <.div()(props.wrapped.message)
  }
  ReactDOM.render(
    <(new MyComponent())(^.wrapped := MyComponent.WrappedProps(message = "Hi"))(),
    mountNode
  )

  This means you can now assign standard props with ease.

  ReactDOM.render(
    <(new MyComponent())(
      ^.id := "my-component",
      ^.wrapped := MyComponent.WrappedProps(message = "Hi")
    )(),
    mountNode
  )

  And access standard props with no workaround (e.g. children method).

  class MyComponent extends StaticReactClassSpec {
    override def render(): ReactElement = <.div()(props.children)
  }

• Use props.children to access children instead of children
• Use RouterProps trait instead of RoutedReactClassSpec[Params] to access router props
  • Use props.history, props.location, and props.match to access router props
• Use <.Provider(^.store := store)(<(App()).empty) instead of <.Provider(store = store)(App())

Close #26