Bump rake from 12.0.0 to 12.1.0
Bump rake from 12.0.0 to 12.1.0

Bumps [rake](https://github.com/ruby/rake) from 12.0.0 to 12.1.0.
- [Changelog](https://github.com/ruby/rake/blob/master/History.rdoc)
- [Commits](https://github.com/ruby/rake/compare/v12.0.0...v12.1.0)
rdunlop/unicycling-rulebook,rdunlop/unicycling-rulebook,rdunlop/unicycling-rulebook,rdunlop/unicycling-rulebook