Ch9 - Add currency test

Chapter 9: Times We're Livin' In, page 39
Ch9 - Add currency implementations

Chapter 9: Times We're Livin' In, page 40
Ch9 - Refactor currency implementations to be the same

Chapter 9: Times We're Livin' In, page 40
Ch9 - Move currency implementation up to Money

Chapter 9: Times We're Livin' In, pages 40-41
Ch9 - Begin Franc initializer refactoring

Chapter 9: Times We're Livin' In, page 41
Ch9 - Update Franc times to use factory method

Chapter 9: Times We're Livin' In, page 41
Ch9 - Complete Franc initializer refactoring

Chapter 9: Times We're Livin' In, pages 41-42
Ch9 - Refactor Dollar initializer same way as Franc

Chapter 9: Times We're Livin' In, page 42
Ch9 - Move common initialization up to Money

Chapter 9: Times We're Livin' In, pages 42-43