Refactoring
Added the wizard as dependency
Fixed gradle build script.

Problem was dependency: java -> groovy.
Default compilation order was:
1.) Java
2.) Groovy

which caused errors telling that groovy objects could not be found.
Fix simply lets groovy handle the entire compilation.
Integrated validation into REST-Service.

Fixed tests.
Added logback config for tests.
Added log files to .gitignore
Merge branch 'validation-integration' into develop