Add initial wrapacker script
Add initial wrapacker script

This does not yet call the actual `packer build` command, but it does
grab the metadata correctly. I'll have to change up the option flag
parsing to include the provider type, then it can just call the complete
command rather than passing options through.

elasticdog/packer-arch,agt-the-walker/packer-arch,aidanharris/packer-arch,slash170/packer-arch,appleby/Lisp-In-Small-Pieces-VM,cosmo0920/packer-arch,dragon788/packer-arch,tomswartz07/packer-arch,tomaspapan/packer-arch