Add notifyOnNetworkStatusChange

[lorensr]

Waiting on: apollographql/react-apollo#2324

Branch 8, after Now we’ve got login working.

export const withUser = graphql(USER_QUERY, {
  options: { notifyOnNetworkStatusChange: true },
  props: ({ data: { currentUser, loading } }) => ({
    user: currentUser,
    loggingIn: loading
  })
})