Add rockspecs

[Alloyed]

This lets people install and manage lume in their projects using luarocks.
To test:

$ luarocks install lume-scm-1.rockspec

If you'd like to upload these to the central luarocks.org service, you can get an API key and do:

$ luarocks upload --api-key=<thekey> lume-scm-1.rockspec
$ luarocks upload rockspecs/lume-2.2.3-1.rockspec

I can also maintain the luarocks.org part if you don't mind the occasional fluffy PR.

[rxi]

I like the idea of this -- I had previously tried to get something going with luarocks; I wasn't able to get it to work, though, possibly due to my distro having an outdated version?

Would you be able to explain the "scm-1" part in the version? And what you mean exactly by the "fluffy" pull requests. I will probably have to read a bit more on the details of how luarocks works but this sounds good otherwise.

[Alloyed]

So long as your distro's package isn't too out-of-date you can do luarocks install luarocks, which will install the latest version into /usr/local. This is what I do on Debian, and it works okay enough.

scm-1 just means that the rockspec tracks the HEAD of your github repo. When you install an scm rock, you always get the very latest public version of that code, which also means if you reinstall it you don't get the same guarantee that you're getting the same thing you got last time. So it's more for development, rather than something you'd depend on in code that you want to ship.

About fluffy PRs, making a new version would also mean having to upload a new package, which also means adding another rockspec file to the git repo. So every once and a while I'd have to ping you just to increment a version number. I guess I can skip that step, but I personally find it nice that you can get a copy of the package even when luarocks.org is down just by going to the upstream repo.

If you have any other questions about luarocks feel free to ask, I probably at least a little bit about it by now~