Drop support for bolt?

[benmccann]

https://www.npmjs.com/package/bolt - less than 2,000 downloads / week
https://github.com/boltpkg/bolt - last commit was 4 years ago

used here:

manypkg/packages/find-root/src/index.ts

Line 9 in e6d32a3

BoltTool,

I'd like to cut a new major for the tools package in #220, but this would be a different package

[Andarist]

cc @steve-taylor