Added country localization based on hexorx/countries
Use `Thread.current` for thread-safeness for now

  * This should probably be changed to use
    [RequestStore](https://github.com/steveklabnik/request_store) since
    I can imagine that `country_select` is used across so many servers
  * I removed `CountrySelect.locale=` because that should be handled
    with `I18n.locale`. I have, however, kept the getter and it just
    returns `I18n.locale`. This seemed the right choice from a
    testing/API-completeness perspective.
Remove unused `DEFAULTS`
Add seeded default hash back. :derp:
Triage Travis CI configuration

  * Use latest rubies for travis
  * Switch to travis-handled rbx version; add dependent gems
  * Use latest appraisal gem that supports Bundler platforms
  * Update appraisal gemfiles to use latest appraisal
  * Add fragile rubies to allowable failures in travis-ci
Merge pull request #1 from scudco/auzroz-localization

Fixup some of the Thread safety issues
Merge pull request #37 from auzroz/localization

Added country localization based on hexorx/countries
Update README code examples
Bump version to 1.3.0

  * 1.2.0 existed for a long time on github without being released. In
    order to prevent confusion around things like the now capitalized
    country codes, releasing 1.3.0 and skipping an official 1.2.0 seems
    appropriate.