Now user data is in roles/users/defaults/main.yml
and each server should have a hash like this

users:
  'foo': sudo
  'bar': true
  'baz': false
  #'qux': false

This means the user foo will be created with sudo
access, the user bar will be created without sudo
access, while baz and qux will be removed.

..so I can log in on a serial port and save the day.
This is one way to generate the hashed password line:

python <<EOF
from passlib.hash import sha512_crypt
import getpass
print(sha512_crypt.using(rounds=5000).hash(getpass.getpass()))
EOF

On the doorputer we want to put every user
in both the dialout group and the sudo group

This way we shouldn't conflict with existing
users. Eg. the 'pi' user on Raspbian