Possibly omitted create-service step, Section 5.2

Thanks for this guide! I followed along and at Step 5.4 (Bootstrapping) the build started to fail due to missing classes.
- MakeService
- ModelService
- VehicleService
Workaround: I looked at some other source and found the command (grails create-service Make, etc.) and then I copied over the 4 service classes you have in the Complete project. Then modified the package name to mine. 