Based on chapter06-02, but with following changes from the exercises:


Customer#newCar
- as @Disabled(When.UNTIL_PERSISTED)

Customer#deleteCar
- as @Disabled(When.UNTIL_PERSISTED)


Car#bookService
- as @Disabled(When.UNTIL_PERSISTED)

Car#delete
- as @Disabled(When.UNTIL_PERSISTED)



reimplemented Service's validate() as specification
- removed Service#validate() method
- added BookedInBeforeEstReadySpecification
- annotated Service with @MustSatisfy(BookedInBeforeEstReadySpecification.class)



AbstractCarFixture
- now uses Customer#newCar to create cars

