Notifying cluster owner when the cluster is to be deleted #176
Description
Currently we send notifications on slack about clusters that are to be deleted in the next days. We need to notify the cluster owner about this update so that he/she can take an action whether to delete the cluster if he/she doesn't need it or extend the cluster ttl using the extend-cluster-ttl.sh script.
To implement this, we would need to:
- Add a mandatory owner tag on requesting a cluster. The value of the owner should be the owner's slack ID.
- Tag the owner in the cluster status slack message.