Provide a command to expire all passwords

[x] Allow the password hash field in the database to be empty - representing an expired password.
[x] Create a command that sets all password fields to empty.
[x] Create a command that sets the password of a user to a specific value. the value may come from command line or from stdin.
[x] Decide and document how conflicts are handled during expiring all passwords. What if a user updates their password while it is being expired?

ISibboI / vocabulary-learning-application