Use sqlite_ext 1.5.0 which has been broadened to work with Ruby
versions prior to 2.x, and remember to add it to files in the
./gemfiles/ directory for use with CI tests, not just to
Gemfile in the root directory.

Fix ambiguous 1st argument warnings in Ruby 2.3.x

Add .ruby-version to .gitignore

Was causing:

    NoMethodError: private method `include' called for
      ActionDispatch::Request:Class

* handles unreachable network exception

* adds network error class

* tests unreachable host exception handling

Change SmartyStreets Zipcode API.

Smarty street's new zipcode api endpoint as of 26 March 2016.
http://status.smartystreets.com/incidents/4hjpfqh9q2k7

SmartyStreets is permanently changing their ZIP Code API endpoint by
June 22 at 9am Mountain Time.  The legacy API endpoint is available
until the 22nd.

This change basically changes the API endpoint and updated the tests to
reflect the change.

try Rack::Request if ActionDispatch::Request is not defined, fixes #1060

Wasn't testing what it claimed to be testing.

Intended to fix #1048.

add `source_country` parameter for esri geocoder

Add Method for Merging Lookup Configuration

ESRI lookup now uses this method.

fix merging esri config when generating a token

This should improve readability and make testing easier as it separates
the various tasks into separate methods.

Add Mapzen reverse geocoding

fix reference to EsriToken, avoid using rails .minutes