* Initial work for streaming app shell way of using serviceworkers
* Close in on serviceworker adjustment finalization
* Add docs and loading indicator
* Remove useless code
* Don't run on API
* Update app/javascript/contentDisplayPolicy/hideBlockedContent.js
* Fix small details
* Don't run serviceworker.js code in test env
* Fix JS in serviceworker
* Move private keyword to proper place in async controller
* Change shell_version to HEROKU_SLUG_COMMIT
* Update caching config
* Add test for async_info/shell_version
* Add article decorator published_timestamp
* Use time HTML5 element and refactor date in partial
* Add published_timestamp to Article
Adding `published_timestamp` to the homepage we can then use JS to render the full timestamp localized for the user.
We've also added the timestamp to the index and the API
* Display article published timestamp on hover
* Use time also in the article show page
* Add timestamp to bottom articles as well
* Remove published_timestamp from index because it is not used
* Fix broken specs
* Add more article dates specs
* Refactor date initializers
