This change adds the `assert-true` and `assert-false` function to our
bash testing framework, together with unit tests.
Also rename the test file to `testing-framework.inc.tests.sh` to match
the implementation file.
This change adds the `--quiet` option to the `run_tests` function of
the testing framework. This will redirect the regular output to a log
file (`/tmp/<testname>.log`) and only output the pass/failed result.
