Update s3.rb

[daniel-burke-hmh]

I read this documentation as stating that I had to provide an exact filename match but I don't think that's correct? I've tried to make it more explicit

[elasticsearch-release]

Jenkins standing by to test this. If you aren't a maintainer, you can ignore this comment. Someone with commit access, please review this and clear it for Jenkins to run; then say 'jenkins, test it'.