Automatic maintenance block

[DavideCristoni]

Add a block to the system, preventing the use of the coffee machine, after a certain amount of coffees have been made. This is to ensure that the machine receives the adequate maintenance, such as descaling. An Idea to this could be to make a special user called "maintenance" or "machine". This user's coffee counter will increment every time a coffee is being made. Every time an user tries to log in into the machine, the system check whether the special user has reached maximum amount of coffee, if that's so the user is being prevented access to the machine. The machine then needs to be cleaned and admins need to reset the maintenance counter.

[gregpetru]

• [ ] Update Esp code for blinking yellow if the maintenance mode is active
• [ ] Manage if the card is the technician card (the card enables the maintenance mode until it is re-read and the led turns green again)
• [ ] Update database for notifications item