This is the best testing RAML framework I've seen and thus I've adopted it. I'm using it to test APIs built in Clojure.
It does the right thing in the sense that, instead of trying to auto-test your API (which can only work for the most naive things), raml-tester invites you to fully cover your API with integration tests and, as you're doing so, validates that the requests and responses conform to the RAML spec and its related schemas.
This is plain genius.
Also, there is a proxy (raml-tester-proxy) that you can use if you don't want or can't embed raml-tester in your project's integration tests. raml-tester-proxy is great for scenarios where QA would build an independent set of tests (maybe by using SOAPui and its RAML plugin) and thus would not want to alter the embedded integration tests of a project.
Big thank you Stephan, this is an awesome contrib.