[bug] Support <Context.Provider /> + <Context.Consumer /> components

[koulmomo]

Type of issue

Both a feature and a bug. Bug because any apps trying to render using the new context api are broken.

Description

If your react tree contains <Provider /> or <Consumer /> components created using the new React v16.3.0 createContext API

const {Provider, Consumer} = React.createContext(false);

<Provider value={this.state.foo} />

<Consumer>
  {isFoo => {
    return isFoo ? <Foo /> : <Bar />
  }}
</Consumer>

Current behavior

Type error with message:

fatal: type is not a function stack=TypeError: type is not a function
    at prepareElement (FUSION_APP_DIR/node_modules/fusion-react-async/src/prepare.js:64:28)
    at _prepare (FUSION_APP_DIR/node_modules/fusion-react-async/src/split.js:12:7)
    at Promise.all.React__default.Children.toArray.map.child (FUSION_APP_DIR/node_modules/fusion-react-async/src/split.js:14:1)
    at Array.map (<anonymous>)
    at prepareElement.then (FUSION_APP_DIR/node_modules/fusion-react-async/src/split.js:15:42)
    at <anonymous>
    at process._tickDomainCallback (internal/process/next_tick.js:228:7), message=type is not a function, captureType=request

Expected behavior

It should be able to handle react tree that contains <Provider /> + <Consumer /> component from the new React.createContext() api.

Preliminary investigation shows that we can detect if the type of an element is a context-consumer|provider type (or even Fragment type) using the react-is package.