it sometimes happens that one forgets to add `.run().ok()` to a command, leading to things not actually being tested, potentially even slipping though code reviews! This commit adds a check at fixture teardown time, checking that all commands have been run. Sadly, due to when this check happens, we cannot add a test checking for this behavior Change-Id: If3df2c20c267b9f03ae0ca099b77c57e2310f335