Use Dokku to auto-deploy branches pushed to Github.
By default it will create and deploy apps based on branches pushed and named demo/<name>, where <name>
is anything you want. This will create a Dokku app named <repo-name>-<name>, deploy to it, and optionally
setup a Let's Encrypt cert for it. You can also tell it other specific branches to deploy (e.g. master or prod).
This should be able to fully replace Heroku's GitHub integration including it's Review Apps.
If you are using the dokku-require plugin the required volumes
will be created for you via the app.json file; otherwise you can set them up manually following the
install instructions.