Some cleanups in the Spring Data JPA example.

Moved repositories into service package to be able to make them package private and thus only expose the service interfaces to clients. Merged HotelRepository and HotelSummaryRepository. Made service implementations package protected as well.

Introduced integration test base class to bootstrap the app as SpringAppliation.run(…) would. Refactored central test case to rather use Spring MVC integration testing framework. Added integration tests for repositories to execute query methods.

Added logging config for Logback.