Make a quiet flag for the virtual quad

The virtual quad tests in quad/scripts/tests are way too verbose, primarily due to the motor outputs printing to the screen. To ensure the test logs are concise, we should build a quiet flag into the virtual quad, or have some way of redirecting the output during the test.

@phjones

added In Progress label

assigned to @bbartels

closed via commit 2e7e1690

mentioned in commit 2e7e1690

removed In Progress label

mentioned in issue #75 (closed)