Use strainer for chef checks when possible

This way, we get a per-cookbook possibility to set test-specific
options.  For example, a certain cookbook might want to be more or less
strict with foodcritic and could then handle that from the cookbooks
Strainerfile.  In addition to that, its is transparent for cookbook
contributors to figure out what test get run by jenkins.

Change-Id: I0353b8207abb116ea3849c04df39546f8c2625db
Merge "Use strainer for chef checks when possible"