Bucket Replication Support

[davidski]

Thanks for the very handy module!

I've recently needed to add S3 replication to a bucket managed by this module. Unfortunately, the replication configuration is a part of the s3_bucket resource and can't be modified independent of that resource in Terraform. That means this module would have to support optional replication configuration.

My goal is to get support for configuring a buckets created by this module to be replication sources. Specifically looking at cross-account, same-region, replication support. Support for creating the replication service roles would be a nice to have as well. 😄

[joe-niland]

@davidski it looks like S3 replication support was added in #56 but I guess you would have solved it by now! :D