The other answer suggested modifying your folder structure to have shared folder for integration and acceptance tests, but you can have the original folder structure as well. Also you mentioned in the comment you want to keep all three (including not-mentioned integration tests) separate, which is possible, though hackish.
Since you seem to have test/unit for unit tests and test/acceptance for acceptance test, I'm assuming test/integration for integration tests.
Note though that separation only applies for sources: compiled files will all go to the same folder, and AFAIK that's something you can't change. This means you need to have naming strategy for your tests to separate them from each other.