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

Disable SSL v2 and v3 if ssl enabled

* Support for a custom telize endpoint

* fix path

Add result_type as option for google lookup

The #latitude and #longitude methods are defined in the Base lookup. The
intention is that subclasses implement #coordinates only, as it results
in less code duplication.

* 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

* Use proper domain name

Use pro.ip-api.com domain in case when api key is in use, otherwise just ip-api.com.

* Handle invalid api key

* Add forsaken fixture

* Make uniform an invalid key handler with the other geocoder lookups

Enabling ESRI for storing results

change freegeoip lookup's host from freegeoip.net to freegeoip.io