This is a utility that can used to help with version bumping.
Right now the target is just to use it in scripting with SemVer versions, but I
could see expanding it into other version schemes being useful as well.
Other potential plans involve configuration for automatically bumping versions
in various projects/formats (e.g. bump a package version in `Cargo.toml`).
The first goal is just to have versions read in via `stdin`, possibly also on
the command line.