Feature request - luarocks

Given lua is installed out of the box, having access to the package manager luarocks would be a natural complement.

I recognise that this may be highly challenging if not impossible, since many many luarocks are wrappers around C libraries that are presumably not portable (or automatically portable). I don't know whether luarocks provides an easy way to screen out / reject any packages than are not pure Lua. The [rockspec format](https://github.com/luarocks/luarocks/wiki/Rockspec-format) MAY be possible to identify pure Lua functions with a few heuristics I suppose.

Otherwise I guess it would be fine if non-pure Lua packages just died at some phase of the luarocks installation process :)