collectionsPath appends to the correct slice
collectionsPath appends to the correct slice

Fixes what would have been a failure if roles+collections were tested at
once

ricardclau/packer,hashicorp/packer,ricardclau/packer,rnaveiras/packer,hashicorp/packer,pecigonzalo/packer,hashicorp/packer,ricardclau/packer,pecigonzalo/packer,mitchellh/packer,pecigonzalo/packer,rnaveiras/packer,mitchellh/packer,rnaveiras/packer,rnaveiras/packer,ricardclau/packer,mitchellh/packer,hashicorp/packer,mitchellh/packer,rnaveiras/packer,ricardclau/packer,pecigonzalo/packer,rnaveiras/packer,ricardclau/packer,mitchellh/packer