Travis passes builds despite failing tests

[sindrehan]

Even though some/most of the tests are failing, Travis displays the build as passing.
I suspect that the reason for this is that the errors from rostest is not being passed out to the Docker-container and thus the build never fails.

Errors from roslint exit with a non-zero code, so the problem definetly lies with rostest.

Here is a log with failing tests, but a passing build.