packaging: Publish package on Homebrew

[RobotSail]

Systems like these are also frequently paired with package managers like homebrew which allow software installations in user-space.

It would be a great way to redistribute this software if it could be conveniently installed with a command like:

brew tap russellb/canhazgpu
brew install canhazgpu

[russellb]

I like it. I've never packaged anything for brew, but I use it! I'm happy to merge whatever is needed for this.