Bumps [countries](https://github.com/countries/countries) from 5.7.1 to 5.7.2.
- [Release notes](https://github.com/countries/countries/releases)
- [Changelog](https://github.com/countries/countries/blob/master/CHANGELOG.md)
- [Commits](countries/countries@v5.7.1...v5.7.2)

---
updated-dependencies:
- dependency-name: countries
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

The countries gem got updated so a few things had to be changed as well.
The key difference here is that a few translations are different and
the Czech language is no longer associated with Slovakia.

I also updated the rakefile to automatically run the outdated readme
and cache checks when run with no arguments.