Travis CI for homework automatic testing and grading

I know I can include tests in the starter code and do automatic testing using Travis CI on Github Push(s).

I would prefer to keep the tests on the Travis CI side - hidden from the students. Is this possible?

I would also like to report the test results to an external database. Is this possible?

If Travis CI cannot do it, are there any recommendations on alternatives services, CI or other. I would prefer something with Github integration.