support both multiple_choice? and multiple_choices?

lib/httparty/response.rb

@@ -40,6 +40,11 @@ def inspect
       end
     end
 
+    # Support old multiple_choice? method from pre 2.0.0 era.
+    if ::RUBY_VERSION >= "2.0.0"
+      alias_method :multiple_choice?, :multiple_choices?
+    end
+
     def respond_to?(name)
       return true if [:request, :response, :parsed_response, :body, :headers].include?(name)
       parsed_response.respond_to?(name) || response.respond_to?(name)

spec/httparty/response_spec.rb

@@ -170,7 +170,7 @@ def response_mock(klass)
         :length_required?                 => Net::HTTPLengthRequired,
         :method_not_allowed?              => Net::HTTPMethodNotAllowed,
         :moved_permanently?               => Net::HTTPMovedPermanently,
-        :multiple_choices?                => Net::HTTPMultipleChoice,
+        :multiple_choice?                 => Net::HTTPMultipleChoice,
         :no_content?                      => Net::HTTPNoContent,
         :non_authoritative_information?   => Net::HTTPNonAuthoritativeInformation,
         :not_acceptable?                  => Net::HTTPNotAcceptable,
@@ -195,7 +195,14 @@ def response_mock(klass)
         :unsupported_media_type?          => Net::HTTPUnsupportedMediaType,
         :use_proxy?                       => Net::HTTPUseProxy,
         :version_not_supported?           => Net::HTTPVersionNotSupported
-      }.each do |method, klass|
+      }
+
+      # Ruby 2.0, new name for this response.
+      if RUBY_VERSION >= "2.0.0"
+        SPECIFIC_CODES[:multiple_choices?] = Net::HTTPMultipleChoices
+      end
+
+      SPECIFIC_CODES.each do |method, klass|
         it "responds to #{method}" do
           net_response = response_mock(klass)
           response = HTTParty::Response.new(@request_object, net_response, '')