Release 3.1.0

Changes

Improvement: Provide listCountryCodes() call as a symmetric replacement for now deprecated listCountries(). #123
Deprecation: Deprecated listCountries() since the HTTP API has deprecated all country fields in favor of ISO 3166-1 country codes. #123
Improvement: Provide new List<> returning call for advanced search. #126
Bugfix: Use view boundary on Stream<> returning calls. The stream will page through the view. #126
Minor library updates (slf4j, hamcrest, lombok, wiremock, etc).
Minor Maven plugin updates.