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

* alex/master:
  Prepare for release of gem version 1.3.3.
  Add ip api com lookup
  Fix mime-types-data error for JRuby
  Remove OAuth util.
  Escaped pluses no longer possible without :yahoo.
  Fix "ambiguous first argument" warnings.
  Add README section about geocoding performance.
  Remove Yahoo BOSS support. The Yahoo BOSS Placefinder API is being discontinued.

* 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

No longer needed now that :yahoo lookup is gone.

Remove Yahoo BOSS support.

Service was discontinued.

- public token generation
- esri token object

- `api_key` param
- `forStorage` param
- token generation
- updating README.md

Added ipinfo.io provider

add pelias/mapzen support