Create Kotlin example app

[gregturn]

Good opportunity to verify things like spring-projects/spring-hateoas#222

[dalbani]

Should someone also run into the same ControllerLinkBuilder related issue as I did, I confirm that the workaround mentioned in comment spring-projects/spring-hateoas#222 (comment) works.
For example something like:

val link = linkTo(MyController::getItems.javaMethod, param1, param2).withSelfRel()