Provide option to use packer boxes with chef pre-installed

[Atalanta]

Installing chef every time is rather slow

[karloscodes]

I agree with this, but i think community needs some much more. It will be very useful if one would be able to customize somehow, box, box_url and chef agent installation on certain environments (by re-using kitchen yml config file or whatever). What do you think?

[crouchr]

The ability to be able to specify my own Vagrant boxes would be extremely useful rather than he opscode built-in ones.