Audit IAM users

### Overview
In order to clean up IAM resources, we need to audit the existing IAM users

### Action Items
In the [IAM console](https://us-east-1.console.aws.amazon.com/iam/home?region=us-east-1#/users), list out:

- IAM users not in terraform
- IAM users that have never logged in
- IAM users that have not logged in in 180 days or more

