[RFE] Add the new 'assume-root' feature

[alexandrosgkesos]

AWS introduced a feature to assume-root of child accounts mainly in order to "fix" bad Deny All S3/SQS policies
It would be good to have this feature implemented in aws-nuke

If "AccessDenied" while listing/deleting SQS/S3,

• assume root with related "task-policy-arn",
• remove or set a default policy
• retry cleanup

Pre-requisites:

• Need to have "IAM - Root access management" Enabled
• IAM entity who cleans up, should have "sts:AssumeRoot" on "arn:aws:iam::*:root"

[ekristen]

Interesting idea. Not sure about the feasibility the way the authentication is currently written. I'd need to implement a way to track task to a particular resource, and a specific error detection w/ secondary auth, but auth happens higher in the stack and we are lower down when the error occurs.

I'm willing to look into this further, but likely won't be for a while.