Set File Expiration

[jmcmains]

Hi, I'd like to be able to set the expiration of the file, so that it automatically deletes itself in S3. I think S3 has this capability built in: http://docs.aws.amazon.com/AmazonS3/latest/dev/intro-lifecycle-rules.html#intro-lifecycle-rules-actions

Thanks!

[qoobaa]

Could you create a PR with the change? Thanks.