Require Chef Infra 15
Require Chef Infra 15

knife-windows v3 removes `knife bootstrap windows winrm` and `knife
boostrap windows ssh` in favor of the functionality moved into core with
Chef Infra 15. We wouldn't want anyone using earlier versions of Chef to
pull in this release.

Signed-off-by: Bryan McLellan <9da9e2973b9c72b95f1bc7169993146760fceeb1@loftninjas.org>

chef/knife-windows,ClogenyTechnologies/knife-windows,MsysTechnologiesllc/knife-windows,ClogenyTechnologies/knife-windows,chef/knife-windows,MsysTechnologiesllc/knife-windows