fix hierarchy for media resource

lib/twilio-ruby/rest/accounts.rb

@@ -8,7 +8,7 @@ def initialize(path, client, params={})
         resource :sandbox, :available_phone_numbers, :incoming_phone_numbers,
           :calls, :outgoing_caller_ids, :conferences, :sms, :recordings,
           :transcriptions, :notifications, :applications, :connect_apps,
-          :authorized_connect_apps, :queues, :usage, :messages, :media
+          :authorized_connect_apps, :queues, :usage, :messages, :media,
       end
     end
   end

lib/twilio-ruby/rest/media.rb

@@ -0,0 +1,12 @@
+module Twilio
+  module REST
+    class Media < ListResource
+      def initialize(path, client, params={})
+        super
+        resource :images
+      end
+    end
+
+    class MediaInstance < InstanceResource; end
+  end
+end

lib/twilio-ruby/rest/messages/media.rb

@@ -1,10 +1,11 @@
 module Twilio
   module REST
-    class Media < InstanceResource
+    class Media < ListResource
       def initialize(path, client, params={})
         super
         resource :images
       end
     end
+    class MediaInstance < InstanceResource; end
   end
 end