It's s3.us-west-2 now, with a dot

features/step_definitions/s3_steps.rb

@@ -1,6 +1,6 @@
 When /^I attach the file "([^"]*)" to "([^"]*)" on S3$/ do |file_path, field|
   definition = Paperclip::AttachmentRegistry.definitions_for(User)[field.downcase.to_sym]
-  path = "https://paperclip.s3-us-west-2.amazonaws.com#{definition[:path]}"
+  path = "https://paperclip.s3.us-west-2.amazonaws.com#{definition[:path]}"
   path.gsub!(':filename', File.basename(file_path))
   path.gsub!(/:([^\/\.]+)/) do |match|
     "([^\/\.]+)"