Support for AWS SSO credentials

[rtimush]

If I try to use a CLI profile configured with SSO, I get the following error:

...com.amazonaws.auth.profile.ProfileCredentialsProvider@2232acfe: No AWS profile named 'my-profile'...

This is probably happening because the library uses AWS SDK v1, while SSO credentials are only supported in the AWS SDK v2.

[sayantacC]

You are right. Loading credentials for a SSO based profile is a missing capability as of now.
We will look into how we can add support for a SSO based profile.
There are different ways forward for us:

1. Upgrading aws-msk-iam-auth to use AWS SDK v2.
2. Or use just the SSO capability from AWS SDK v2 (see Support for AWS SSO credentials aws-sdk-java#2434).

In the meanwhile, I will update the README to call out the missing capability.

[sayantacC]

Update:
I have coded up using sso in a branch https://github.com/aws/aws-msk-iam-auth/tree/sso. Sadly, I have not had the chance to test it out yet. I will look at testing it. In the meanwhile, feel free to give it a spin.

[sayantacC]

Closing this issue as the fix for it has been merged.