LocationIq # for classes
location_iq # for config

* handles unreachable network exception

* adds network error class

* tests unreachable host exception handling

* Add ip-api.com (ip lookup) support

This service returns better coordinates for Europe than other free ip lookup services available in geocoder.

* Clean the results class

Remove default responses for fields.

* Remove checking fields in url query

API already handles unknown fields, so this check is unnecessary.

* Add a test for using parameters directly in search method

TimeoutError is deprecated in Ruby 2.3.0. It has been an alias for
Timeout::Error starting in Ruby 1.8.0, and should be safe to replace.

Test suite failed because railtie wasn't loaded (because
Rails/ActiveRecord are stubbed out in test env). This initializes
it explicitly in test_helper before any models get defined

GeoLite2 is a free version of a product called GeoIP2. Both use the same
format.

Response to GH issues #579 and #663.

This is relevant for SmartyStreets, and seems like a good idea in
general (possibly supported by other APIs).