text: var cacheName = 'weatherPWA-chacha';
  var filesToCache = [
    '/',
    '/index.html',
    '/scripts/app.js',
    '/styles/inline.css',
    '/images/clear.png',
    '/images/cloudy-scattered-showers.png',
    '/images/cloudy.png',
    '/images/fog.png',
    '/images/ic_add_white_24px.svg',
    '/images/ic_refresh_white_24px.svg',
    '/images/partly-cloudy.png',
    '/images/rain.png',
    '/images/scattered-showers.png',
    '/images/sleet.png',
    '/images/snow.png',
    '/images/thunderstorm.png',
    '/images/wind.png'
  ];
  
  self.addEventListener('install', function(e) {
    console.log('[ServiceWorker] Install');
    e.waitUntil(
      caches.open(cacheName).then(function(cache) {
        console.log('[ServiceWorker] Caching app shell');
        return cache.addAll(filesToCache);
      })
    );
  });
  
  self.addEventListener('activate', function(e) {
    console.log('[ServiceWorker] Activate');
    e.waitUntil(
      caches.keys().then(function(keyList) {
        return Promise.all(keyList.map(function(key) {
          if (key !== cacheName) {
            console.log('[ServiceWorker] Removing old cache', key);
            return caches.delete(key);
          }
        }));
      })
    );
    return self.clients.claim();
  });
  
  self.addEventListener('fetch', function(e) {
    console.log('[ServiceWorker] Fetch', e.request.url);
    e.respondWith(
      caches.match(e.request).then(function(response) {
        return response || fetch(e.request);
      })
    );
  });
  