build new docker image

The image here: https://quay.io/repository/jiralert/jiralert-linux-amd64 is not up-to-date any more and also not compatible to the latest example `jiralert.yml`.

```
caller=main.go:75 msg="error loading configuration" path=config/jiralert.yml err="unknown fields in receiver: static_labels"
```

could you please release a new version?