[scaffolding-chef-infra] Intigrate cookstyle cops in to the build test.

[TheLunaticScripter]

There has been a lot of work done to help users transition to Chef 15. One thing that helps with this is running cookstyle against a cookbook to see if it has bad patterns that would hinder a move to Chef 15. We should integrate cookstyle into the build so that we fail a build if we hit a bad pattern.