Add conan package

[peter-moran]

It would be great to have a conan package for this. It's not too hard since this is a header only library.

This would include:

• Write source() to pull files from git
• Handle versioning info via git
• Add ability for run() to perform tests
• Package all header files

This is pretty easy and I could do it myself.

[serge-sans-paille]

Something like that? https://conan.io/center/frozen

[serge-sans-paille]

It's relatively old though.

[peter-moran]

Ah, I forgot that existed. I was thinking it would be easier to maintain the conan package inside this git repo, but based on the way https://github.com/conan-io/conan-center-index is managed, it is probably best practice to have the recipe be external to the project itself.