Feature Request: Option to silence the output from 'exercism configure'

[dmmulroy]

I think it would be useful to have an option with exercism configure command to silence its output. My main use case for this feature is that I would like to have all of my exercises running on a travis ci build and currently it would be publicly outputting my api key when it builds.

[dmmulroy]

PR opened here: #366

[kytrinyx]

That's a great idea.