Manager shutdown reporting

[dgasmith]

Is your feature request related to a problem? Please describe.
It would be good if a manager could (optionally) send out an email upon shutdown and possibly upon a few other actions. This turns out to be straightforward to do in Python:

import smtplib, ssl

port = 465  # For SSL
smtp_server = "smtp.gmail.com"
sender_email = "my@gmail.com"  # Enter your address
receiver_email = "your@gmail.com"  # Enter receiver address
password = input("Type your password and press enter: ")
message = """\
Subject: Hi there

This message is sent from Python."""

context = ssl.create_default_context()
with smtplib.SMTP_SSL(smtp_server, port, context=context) as server:
    server.login(sender_email, password)
    server.sendmail(sender_email, receiver_email, message)

We would likely recommend building a dummy account to do this, but fits in well to our current structure and can be called during the shutdown procedure.