email/notifications for condor jobs

Description of issue

bilby_pipe.job_creation.node.Node().notification = False

Because this is hardcoded to False notifications are never sent on completion of condor jobs.

Suggestion

1. Node().notification could be set to be optional, and allow the user to enter the string "Always" | "Complete" | "Error" | "Never" in the ini.

(Note: when Node().notification=False, notification="Never" in the condor sub file)

2. We could add a condor extra line notify_user = <email-address> only when a user provides the email arg. Otherwise, notification will be sent to the "owner of the HTCondor job".