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

* 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.

Added ipinfo.io provider

add pelias/mapzen support

Remove verbose from rake options due to jruby and rbx failing on travis

Suppress Geocoder API warning when no results are returned

Add support for the LatLon.io geocoder service

add maxmind_geoip2 setup to README.md

Add supported_protocols to Freegeoip.rb lookup

I uncovered a small issue when switching from Yahoo BOSS to Google (with API, which requires enabling :use_https).  Because the Freegeoip.rb file is missing a supported_protocols method, it attempts to do an https lookup for IP lookups when enabling :use_https.

I already tested this on my setup and it appears to resolve the issue, with lookups/base.rb detecting that https is not supported for Freegeoip

Replace TimeoutError with Timeout::Error

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.

The Yahoo BOSS Placefinder API is being discontinued.

https://developer.yahoo.com/boss/placefinder/

Add viewport method to results that provide one

Warn that the Yahoo BOSS Placefinder API is being discontinued.

https://developer.yahoo.com/boss/placefinder/

the Yahoo lookup will be fully removed via:
https://github.com/alexreisner/geocoder/pull/985