Console log breaks quiet builds

[Ramblurr]

We're using broccoli-livingstyleguide as part of our builds on our CI server. One requirement is that we use the --silent flag to ember test so that only the test output is written to stdout. However this package is writing to stdout without any way to turn it off.

Specifically this line here.

It would be great if that line is removed, or guarded depending on whether ember-cli is using the --silent flag.

[hagenburger]

Sounds legit. Do you want to open a pull request?