only print out Writing message when not in quiet mode

Apologies if this isn't the correct way to go about submitting this fix, this is my first time using github to submit a change to a project.

Also, if you don't think this is useful or needed that's fine, I've already changed this locally for our use at my company.

This was problematic for us because we have a cronjob that runs compass, and because of these printouts and email was getting sent out.  We needed the ability to silence all non-error messages.