Log Message:
Add py-aws-sso-util: Smooth out the rough edges of AWS SSO

AWS IAM Identity Center (formerly AWS SSO) has some rough edges, and
aws-sso-util is here to smooth them out, hopefully temporarily until AWS
makes it better.

aws-sso-util contains utilities for the following:

* Configuring .aws/config
* Logging in/out
* AWS SDK support
* Looking up identifiers
* CloudFormation