Update Rakefile to work with newer version of rubyforge library
Update Rakefile to work with newer version of rubyforge library

sauberia/aws-s3,GSA/aws-s3,appfolio/aws-s3,spatten/aws-s3,github/aws-s3,lantrix/aws-s3,jwarchol/aws-s3,AlphaStaxLLC/aws-s3,nagash/aws-s3,International/aliyun-oss-sdk-for-ruby,square/aws-s3,lantrix/aws-s3,mmontalvo/aws-s3,marcel/aws-s3,mangege/aliyun-oss-sdk-for-ruby,gentoo/aws-s3,github/aws-s3,mmontalvo/aws-s3,AlphaStaxLLC/aws-s3,felixbuenemann/aws-s3,mDialog/aws-s3,chef/aws-s3,michaeldwan/sss,dctanner/aws-s3,International/aliyun-oss-sdk-for-ruby