Use the new bento slug names in kitchen
Use the new bento slug names in kitchen

We now publish simpler version slug names so centos-6.9 is also centos-6 and when 6.10 is released it will point to centos-6.

Signed-off-by: Tim Smith <764ef62106582a09ed09dfa0b6bff7c05fd7d1e4@chef.io>

sethvargo-cookbooks/swap,sethvargo-cookbooks/swap,sous-chefs/swap