rostest silently ignores a segfault in a test program

[rhaschke]

An attentive user noticed that a segfault in a test was not detected in our MoveIt CI. Instead, rostest returned 0 with the following output:

[ROSTEST]-----------------------------------------------------------------------

SUMMARY
 * RESULT: SUCCESS
 * TESTS: 0
 * ERRORS: 0
 * FAILURES: 0

However, running the test python program, results in error code 139 (segfault) and the corresponding stderr output: Segmentation fault (core dumped)

Looks like, rostest doesn't notice the segfault.