Allow homebrew to pull pre-built binaries for current version

[zph]

We can do that also. People want/expect the ability to compile if desired.

What we could do is setup homebrew to either get most recent release, OR compile from scratch if wanting it built from master.

If you like that approach, I'll break out a follow up task to address.

Originally posted by @zph in https://github.com/toumorokoshi/tome/pull/4#discussion_r598156045