My guardfile is setup properly and guard runs fine, but I have to manually trigger the tests every time I want them to run. The whole purpose of guard is that it is supposed to monitor your files and run your tests any time they change. I don't know if there is something wrong with the Nitrous.io environment or my settings.
If you need more information just ask and I'll update my question.
Guard supports polling, please try to launch guard with bundle exec guard -p.