Fix presenter to work with new API adapters
Move fixture_file helpers tso they're available more widely
Prevent timecop teardown clobbering other teardowns

This was preventing the Webmock reset from happening
First pass at models to wrap worldwide API
Load all pages of world_locations

Also filter out any results that are a different format (e.g. International delegations)
Refactor country integration tests ready for API
country_select can now use worldwide API data
Point public prod worldwide API in development

We won't normally have whitehall running, so this makes development easier.
Really fix the teardown

after_teardown is only available in the gem version of minitest, not the version shipped with ruby.
Add == method to WorldLocation
Add caching to WorldLocation.all
Add caching to WorldLocation.find
Raise original exception if no stale value in cache