RDS and other secrets in S3 state

Not sure if this belongs here or in the main bitops repo. I'm not super familiar with terraform, but I noticed that some secrets are being stored in the state in S3.

Terraform does warn users that sensitive information such as credentials may be stored in the state, and it also mentions some possible solutions such as using "ephemeral" resources to manage sensitive states. It may add some undesirable overhead, but it's something we could look into.