Removes dead code

* `AWS::Core` is an AWS SDK v1 API, we can drop it
* We don't use the "I attach a" cucumber step

cucumber/paperclip_steps.rb

-When /^I attach an? "([^\"]*)" "([^\"]*)" file to an? "([^\"]*)" on S3$/ do |attachment, extension, model|
-  stub_paperclip_s3(model, attachment, extension)
-  attach_file attachment,
-              "features/support/paperclip/#{model.gsub(" ", "_").underscore}/#{attachment}.#{extension}"
-end
-

lib/paperclip/storage/s3.rb

@@ -126,21 +126,6 @@ module Paperclip
           raise LoadError, "paperclip does not support aws-sdk versions 2.0.0 - 2.0.33.  Please upgrade aws-sdk to a newer version."
         end
 
-        # Overriding log formatter to make sure it return a UTF-8 string
-        if defined?(::Aws::Core::LogFormatter)
-          ::Aws::Core::LogFormatter.class_eval do
-            def summarize_hash(hash)
-              hash.map { |key, value| ":#{key}=>#{summarize_value(value)}".force_encoding('UTF-8') }.sort.join(',')
-            end
-          end
-        elsif defined?(::Aws::Core::ClientLogging)
-          ::Aws::Core::ClientLogging.class_eval do
-            def sanitize_hash(hash)
-              hash.map { |key, value| "#{sanitize_value(key)}=>#{sanitize_value(value)}".force_encoding('UTF-8') }.sort.join(',')
-            end
-          end
-        end
-
         base.instance_eval do
           @s3_options     = @options[:s3_options]     || {}
           @s3_permissions = set_permissions(@options[:s3_permissions])