Service Worker termination by a timeout timer was canceled because DevTools is attached

var path = require('path');
var webpack = require('webpack');
var SWPrecacheWebpackPlugin = require('sw-precache-webpack-plugin');

module.exports = {
  devtool: 'source-map',
  context: __dirname,
  entry: {
    main: path.resolve(__dirname, './client/app'),
  },
  output: {
    path: path.join(__dirname, '/public'),
    filename: 'bundle.js',
    publicPath: '/public/'
  },
  plugins: [
    new webpack.optimize.OccurenceOrderPlugin(),
    new webpack.DefinePlugin({
      'process.env': {
        'NODE_ENV': "'production'"
      }
    }),
    new webpack.optimize.UglifyJsPlugin({
      compressor: {
        warnings: false
      }
    }),
    new SWPrecacheWebpackPlugin(
      {
        cacheId: 'flamingoCity',
        filename: 'my-service-worker.js',
        stripPrefix: path.join(__dirname, 'public').replace(/\\/g,"/"),
        maximumFileSizeToCacheInBytes: 6194304,
        minify: true,
        runtimeCaching: [{
          handler: 'cacheFirst',
          urlPattern: /[.]mp3$/,
        }],
      }
    ),
  ],
  module: {
    loaders: [
    // js
    {
      test: /\.js$/,
      loaders: ['babel'],
      include: path.join(__dirname, 'client')
    },
    // CSS
    { 
      test: /\.styl$/, 
      include: path.join(__dirname, 'client'),
      loader: 'style-loader!css-loader!stylus-loader'
    }
    ]
  }
};

/*
  Import Dependencies
*/
import React from 'react';
import { render } from 'react-dom';
import { Provider } from 'react-redux';
import { Router, Route, IndexRoute } from 'react-router'
import 'babel-polyfill';

/*
  Import Components
*/
import App from './components/App';
import Single from './components/Single';
import PhotoGrid from './components/PhotoGrid';

/* Import CSS */
import css from  './styles/style.styl';

/* Import our data store */
import store, { history } from './store';

/*
  Error Logging
*/

import Raven from 'raven-js';
import { sentry_url } from './data/config';
if(window) {
  Raven.config(sentry_url).install();
}

/*
  Register Service Worker
*/

if('serviceWorker' in navigator  && process.env.NODE_ENV === 'production') {
  navigator.serviceWorker.register('./my-service-worker.js').then(function(reg) {
  // updatefound is fired if my-service-worker.js changes.
  reg.onupdatefound = function() {
    // The updatefound event implies that reg.installing is set; see
    // https://slightlyoff.github.io/ServiceWorker/spec/service_worker/index.html#service-worker-container-updatefound-event
    var installingWorker = reg.installing;

    installingWorker.onstatechange = function() {
      switch (installingWorker.state) {
        case 'installed':
          if (navigator.serviceWorker.controller) {
            // At this point, the old content will have been purged and the fresh content will
            // have been added to the cache.
            // It's the perfect time to display a "New content is available; please refresh."
            // message in the page's interface.
            console.log('New or updated content is available.');
          } else {
            // At this point, everything has been precached.
            // It's the perfect time to display a "Content is cached for offline use." message.
            console.log('Content is now available offline!');
          }
          break;

        case 'redundant':
          console.error('The installing service worker became redundant.');
          break;
      }
    };
  };
  }).catch(function(e) {
    console.error('Error during service worker registration:', e);
  });
}

/*
  Rendering
  This is where we hook up the Store with our actual component and the router
*/
render(
  <Provider store={store}>
    { /* Tell the Router to use our enhanced history */ }
    <Router history={history}>
      <Route path="/" component={App}>
        <IndexRoute component={PhotoGrid} />
        <Route path="/view/:postId" component={Single}></Route>
      </Route>
    </Router>
  </Provider>,
  document.getElementById('root')
);