Update dependencies

Hi guys,

3 minor updates:
- Use https://rubygems.org (instead of :rubygems which is deprecated)
- gem countries: 0.8.4 to 0.9.2
- gem phony: 1.7.12 to 1.9.0

rake test result:
```sh
227 tests, 509 assertions, 0 failures, 0 errors, 0 skips
```

Thanks!