Add rockspec for 3.1.5

[Alloyed]

Adding so bump.lua can be managed with LÖVERocks.
To avoid PR spam, I'll just mention that I have similar rockspecs in for tween.lua, gamera, and anim8 in this test repo
If possible, can you also upload the rockspecs to luarocks.org so it can be used without a custom repository? Thank you.

[kikito]

Hey, thanks a lot for this!

I have merged this and uploaded it to luarocks.

I will add the rockspecs for tween, gamera and anim8 now. Thanks again for writing them!

[kikito]

I have had second thoughts about this.

I have uploaded bump and tween rockspecs (again, thanks!) but I have second thoughts about gamera and anim8.

The difference between bump.lua/tween.lua and gamera/anim8 is that the first two work well in Lua by itself, but the later two only work inside LÖVE. I am not sure I want to "pollute the official luarocks folder" which something which does not work in all versions of Lua.

I would not object so heavily if there was some kind of namespace for the rocks which only work with LÖVE. I am thinking about naming the rockspecs something like love-gamera and love-anim8 instead, so that it is clear that these only work with LÖVE. What do you think?

[Alloyed]

That seems fine to me for clarity reasons, but I am a little worried by the fact that the name of the luarocks package and the name of the lua module would be different in that case.

Where luarocks will tell you ahead of time if you try to upload/install a package with the same name as another package, if "my-great-package.rockspec" and "your-great-package.rockspec" both install a module called "great", the only way to tell there's a conflict is to actually try to require("great") in application code and get the wrong one.

So I'd be more comfortable if you also changed the module name in the build table if you go down that route.