Add NotImplementedError to Bicycle#default_tire_size
Add spares to Bicycle and merge raodBoke spares to super (p131)
Add methods to RecumbentBike without calling super merges spares (p133)
Decoupled sub and super classes, removed dependency to call super in subclass (p134-138)
Add Schedule
Add schedule to Bicycle
Add Schedulable to Bicycle (p149)