alert when scripts are cached

Author: alvarogarcia7

src/registerServiceWorker.js

@@ -29,7 +29,7 @@ export default function register() {
                   // 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 cached for offline use.');
+                  alert('Content is cached for offline use.');
                 }
               }
             };