* Enhancement: Add Docker Hub image
* Push to ghcr.io
* Add all `org.opencontainers.image.xxx` labels using `--label` instead of `LABEL`
* Change `php-fpm` to listen on `:9000` to expose prometheus metrics via `php-fpm_exporter`
* Include `yarn.lock` to speed up builds
* Reorder
* Use correct sha for pr
* Add logging before overriding values in config
* Add `DEBUG=true` env var for verbose `entrypoint.sh` logs
* Print php exception when snappymail fails to generate data directory and config file on the very first time
* Log snappymail version
* Fix COPY statement
* Add .dockerignore
* Add `USER` and `ENTRYPOINT`
* Update `.dockerignore`
* Add docker image test
* Push only if image test succeeds
* Log when startup is successful
* Use plain `docker build` in `build_and_test.sh`
* Fix test output
