MockHttpResponse should return headers how net/http response does

lib/geocoder/lookups/bing.rb

@@ -58,7 +58,7 @@ module Geocoder::Lookup
 
     def check_response_for_errors!(response)
       super
-      if response.headers['X-MS-BM-WS-INFO'] == 1
+      if response['x-ms-bm-ws-info'].to_i == 1
         # Occasionally, the servers processing service requests can be overloaded, 
         # and you may receive some responses that contain no results for queries that 
         # you would normally receive a result. To identify this situation, 

test/test_helper.rb

@@ -124,7 +124,7 @@ module Geocoder
         if file == "bing_service_unavailable"
           filepath = File.join("test", "fixtures", file)
           s = File.read(filepath).strip.gsub(/\n\s*/, "")
-          MockHttpResponse.new(body: s, code: "200", headers: {'X-MS-BM-WS-INFO' => 1})
+          MockHttpResponse.new(body: s, code: "200", headers: {'x-ms-bm-ws-info' => "1"})
         else
           super
         end
@@ -424,7 +424,7 @@ class GeocoderTestCase < Test::Unit::TestCase
 end
 
 class MockHttpResponse
-  attr_reader :code, :body, :headers
+  attr_reader :code, :body
   def initialize(options = {})
     @code = options[:code].to_s
     @body = options[:body]
@@ -432,6 +432,6 @@ class MockHttpResponse
   end
 
   def [](key)
-    send key if respond_to?(key)
+    @headers[key]
   end
 end