Add test for disk input validation
Add test for disk input validation

mitchellh/packer,dave2/packer,mitchellh/packer,grubernaut/packer,mitchellh/packer,paulmey/packer,hashicorp/packer,paulmey/packer,ricardclau/packer,rnaveiras/packer,hashicorp/packer,pecigonzalo/packer,ricardclau/packer,grubernaut/packer,hashicorp/packer,ricardclau/packer,rnaveiras/packer,rnaveiras/packer,ricardclau/packer,timsutton/packer,pecigonzalo/packer,timsutton/packer,rnaveiras/packer,paulmey/packer,paulmey/packer,paulmey/packer,grubernaut/packer,pecigonzalo/packer,dave2/packer,dave2/packer,pecigonzalo/packer,grubernaut/packer,hashicorp/packer,mitchellh/packer,grubernaut/packer,timsutton/packer,ricardclau/packer,timsutton/packer,timsutton/packer,paulmey/packer,dave2/packer,timsutton/packer,dave2/packer,grubernaut/packer,ricardclau/packer,rnaveiras/packer,rnaveiras/packer,mitchellh/packer,dave2/packer