Fail when no test run

[martinda]

This ensures the problem that was solved in #76 does not repeat itself.

[tudortimi]

Doesn't this fail, since we don't have any unit tests?

[martinda]

Well, two part answer: 1) there are functional tests, and they are of type Test, so that should work; except that 2) it does not. I commented out the functionalTest task, and it does not fail. I was sure I had tried it though. Not sure what's going on.

[martinda]

For reasons beyond my current understanding, this appears non-trivial. Some links I want to study for my understanding:

• Introduce an easy fail if no tests config option gradle/gradle#7452
• https://stackoverflow.com/questions/26147480/how-to-make-gradle-not-to-mark-build-failed-if-no-tests-are-found
• https://stackoverflow.com/questions/53963708/execute-gradle-task-after-test