Mostly a test to see how Renovate behaves here.
It updated from `0.11.0` to `0.12.0`, even though `0.12.7` was available
at that point. While this doesn't matter for Cargo, Renovate seems to
use `Cargo.toml` to calculate the changelog entries, not `Cargo.lock`.
So because `Cargo.toml` specified `0.11.0`, PR #60 showed changelogs for
all tags since then, even though `Cargo.lock` was at `0.11.27`. So there
were 27 pointless changelog entries shown.
So this test is to see whether Renovate will always use the `x.0`
version in `Cargo.toml`, or if having `0.12.7` now will trigger it to
eventually go to some `0.13.x`, where `x > 0`.