Elevator

Features:

• 6 floors
• each floor has a panel with 2 buttons up/down
• inside elevator panel 0 -> 6
• status logger (next floor, going up, going down)
• time floor to floor 3 seconds
• the lift should stop if requested for same direction on its way to target floor
• the lift favours direction vs requests chronology

TODO

• rewrite decideNextTarget fn (it's horrible)
• handle outside requests edge cases
• solve case when calling elevator for the same floor as the current one
• simulate elevator translation between floors