Heroku-16 stack is now generally available

Change effective on 11 April 2017

Heroku-16, our stack based on Ubuntu 16, is now generally available. If your organization uses review apps, we recommend testing Heroku-16 by defining your stack in app.json:

   "stack": "heroku-16"

You can then upgrade your app by running:

$ heroku stack:set heroku-16

To learn more about testing and upgrading your app, check out the documentation.