[DO NOT MERGE, ONLY FOR DISCUSSION]Adjust number of floors for customer

You can see the changes i've done in the Custome class. This is okay for that class, but it'll be a bit messy for the elevator and the building. 

- It'll be messy when moving the lift and when comparing the positions of the customers respect to the lift

Can you suggest a different approach?

- We could proceed having an INT arrayList of floors where we will remove the 13th floor and append one at the end of the list.