Update geocodio.rb

Guard for nil loc in parse_json

Author: tgraham

lib/geokit/geocoders/geocodio.rb

@@ -28,7 +28,7 @@ def self.parse_json(json)
             loc.all.push(create_new_loc(address))
           end
         end
-        loc.success = true
+        loc.success = true unless loc.nil?
         loc
       end