Fix for undefined error when starting react-native app with ignite boilerplate

ReduxNavigation.js

import React from 'react'
import * as ReactNavigation from 'react-navigation'
import { connect } from 'react-redux'
import AppNavigation from './AppNavigation'

// for react-navigation 1.0.0-beta.30
import {
  createReduxBoundAddListener,
  createReactNavigationReduxMiddleware,
} from 'react-navigation-redux-helpers';

const middleware = createReactNavigationReduxMiddleware(
  "root",
  state => state.nav,
);
const addListener = createReduxBoundAddListener("root");
// end for react-navigation 1.0.0-beta.30


function ReduxNavigation (props) {
  const { dispatch, nav } = props
  const navigation = ReactNavigation.addNavigationHelpers({
    dispatch,
    state: nav,
    addListener // <-- add this as well
  })

  return <AppNavigation navigation={navigation} />
}

const mapStateToProps = state => ({ nav: state.nav })
export default connect(mapStateToProps)(ReduxNavigation)