Pin to working version of commonmaker
Pin to working version of commonmaker

Commonmarker changed their parse options and tilt hasn't added the
change yet this pins to the last working version.

puppetlabs/pltraining-bootstrap,kjhenner/pltraining-bootstrap,kjhenner/pltraining-bootstrap,puppetlabs/pltraining-bootstrap,samuelson/pltraining-bootstrap,joshsamuelson/pltraining-bootstrap,puppetlabs/pltraining-bootstrap,samuelson/pltraining-bootstrap,binford2k/pltraining-bootstrap,joshsamuelson/pltraining-bootstrap,samuelson/pltraining-bootstrap,kjhenner/pltraining-bootstrap,binford2k/pltraining-bootstrap,joshsamuelson/pltraining-bootstrap,binford2k/pltraining-bootstrap