Add integration/compatibility tests from a jar dependency

I have a basic Gradle java project. I want to run some tests on it from a jar dependency.

dependencies {
 compile "org.listener:listener-app:1.0"
 testCompile "org.listener:listener-app:1.0:tests"
  task compatibilityTest(type: Test) {
 include '**/*StartupTest.class'

So my listener-app:1.0:tests jar can have a series of tests to run to see if the current project is compatible.

I don’t have any tests in the current project, the compatibilityTest task is being skipped because the are no source files.

How can I do this sort of thing?