Generated via git ls-files | xargs perl -pi -e "s/[Cc]opyright (?:\([Cc]\) )?((?\!$(date +%Y))\\d{4})(-\\d{4})?([, ][ \d]+)*(,|(?= ))/Copyright \\1-$(date +%Y),/g"

This is an entirely mechanically generated (chefstyle -a) change, to go
along with chef/chefstyle#5 . We should pick something and use it
consistently, and my opinion is that double quotes are the appropriate
thing.