render () {
    return (
      <Provider store={store}>
        <RootContainer />
      </Provider>
    )
  }
Provides an entry point into our application.  Both index.ios.js and index.android.js
call this component first.

We create our Redux store here, put it into a provider and then bring in our
RootContainer.

We separate like this to play nice with React Native's hot reloading.