Exits with an error if a command is not found, any undefined variable is
used, or a command in a pipeline returns an error.
Should make Travis detect failed tests.
This means test files are imported as modules, not run as scripts. THey
can still be run individually if so desired. Test coverage is measured,
and an html report generated in htmlcov/. Test cases are automativally
discovered, so they need not be listed twice. An overall
passed/failed/skipped summary is printed, rather than for each file.
Arguments passed to ./test are passed on to unit2. For instance
./test -v
will print each test name as it is run.