Add missing response attribute names to array.

lib/geocoder/results/yahoo.rb

@@ -38,6 +38,7 @@ module Geocoder::Result
     def self.response_attributes
       %w[quality offsetlat offsetlon radius boundingbox name
         line1 line2 line3 line4 cross house street xstreet unittype unit
+        city state statecode country countrycode postal
         neighborhood county countycode
         level0 level1 level2 level3 level4 level0code level1code level2code
         timezone areacode uzip hash woeid woetype]