update appveyor from chef 12 to 13
update appveyor from chef 12 to 13

Signed-off-by: Will Fisher <392743f9dc9e2aef3201bd7129e55eb620ce557e@chef.io>

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