ChapterFour: Move CargoBackend to own module
ChapterFour: Move RoutingService to own module
ChapterFour: Move CargoRepoFactory to CargoBackend
ChapterFour: Add CargoService and refactor listCargo use case
ChapterFour: Refactor use case show Cargo
Add API layer to CargoBackend
Switch to Single Page JS App

- Introduce Backbone.js
- Set up frontend application
- Implement RESTful Service with the help of PhlyRestfully ZF2 module
Implement complete booking procedure as single page js app

- New resource RouteCandidate
- Add endpoint to update CargoRouting
- Expand UI functionality
- Adapt book new cargo feature test