Option 1.  We introduced `play-integration-test` so that the tests could make use of everything in `play-test` without introducing a circular dependency between `play-test` and `play`.  Putting it in the same SBT sub project would be ideal, but having them under the same root project is the next best thing, and means you can fire up the SBT console, select the integration test project, and it will still automatically pick up changes in other projects, test-quick works, etc.