Fix system tests failing with Automake

1. .gitlab-ci.yml script for running tests is currently broken as it hides test failures¹.

2. A number of system tests (e.g. rrsetorder) are consistently failing.

We should first make CI jobs fail when tests fail and then fix the failures one by one.

1. ( cd bin/tests/system && make -j${TEST_PARALLEL_JOBS:-1} -k check V=1 ) || cat bin/tests/system/test-suite.log ↩