public/store/configureStore.js

import { createStore, applyMiddleware } from 'redux';
import thunk from 'redux-thunk';
import logger from 'redux-logger';

import rootReducer from '../reducers';

export default function configureStore (preloadedState) {
  const store = createStore(
    rootReducer,
    preloadedState,
    applyMiddleware(thunk, logger())
  );

  return store;
}