The existing Github deployment method works great.

However it could be enhanced with pre/post deployment actions. This way I could a run a db migration script before the deployment and a slack notification after the deployment

The way to implement this would be to allow me to run a command that runs

1. In my project folder

2. With network access to my services (e.g. my postgres)

This is similar to https://devcenter.heroku.com/articles/release-phase