Revert "install golang 1.11 on appveyor machines"
Revert "install golang 1.11 on appveyor machines"

This reverts commit 2af4f4d206662696a06029bc3094d6036c1163f2.

tas50/packer,youhong316/packer,pecigonzalo/packer,paulmey/packer,youhong316/packer,hashicorp/packer,grubernaut/packer,youhong316/packer,tb3088/packer,tb3088/packer,tb3088/packer,bryson/packer,ricardclau/packer,rnaveiras/packer,bryson/packer,hashicorp/packer,tb3088/packer,tas50/packer,tb3088/packer,mitchellh/packer,paulmey/packer,rnaveiras/packer,tas50/packer,mkuzmin/packer,tb3088/packer,dave2/packer,grubernaut/packer,paulmey/packer,mitchellh/packer,pecigonzalo/packer,mitchellh/packer,timsutton/packer,pecigonzalo/packer,timsutton/packer,paulmey/packer,bryson/packer,hashicorp/packer,dave2/packer,grubernaut/packer,youhong316/packer,hashicorp/packer,tas50/packer,youhong316/packer,bryson/packer,timsutton/packer,mkuzmin/packer,dave2/packer,rnaveiras/packer,mkuzmin/packer,timsutton/packer,grubernaut/packer,dave2/packer,mkuzmin/packer,youhong316/packer,mkuzmin/packer,ricardclau/packer,mitchellh/packer,timsutton/packer,dave2/packer,dave2/packer,ricardclau/packer,tas50/packer,paulmey/packer,ricardclau/packer,mkuzmin/packer,rnaveiras/packer,rnaveiras/packer,paulmey/packer,grubernaut/packer,mitchellh/packer,ricardclau/packer,bryson/packer,rnaveiras/packer,grubernaut/packer,pecigonzalo/packer,timsutton/packer,bryson/packer,ricardclau/packer,tas50/packer