appveyor: use 1.9.3 golang
appveyor: use 1.9.3 golang

kiranmeduri/amazon-ecs-agent,aws/amazon-ecs-agent,aws/amazon-ecs-agent,kiranmeduri/amazon-ecs-agent,swipely/amazon-ecs-agent,swipely/amazon-ecs-agent,aws/amazon-ecs-agent,kiranmeduri/amazon-ecs-agent,kiranmeduri/amazon-ecs-agent,swipely/amazon-ecs-agent,aws/amazon-ecs-agent,swipely/amazon-ecs-agent