Add support for awscli v2 sso ~/.aws/config

[ghidinelli]

Hi Tyler - thanks for Saw, super awesome to give us tail like functionality for cloudwatch.

I've got the docker-based install working with ~/.aws/credentials, however my org uses AWS SSO so I'm trying to get it to work with the new aws cli v2 sso login. This uses ~/.aws/config.

When I try to use a profile I've logged in named "prod", I get this:

~ $ saw watch /ecs/ColdFusionApp --profile prod --region us-east-1
Error NoCredentialProviders: no valid providers in chain. Deprecated.
	For verbose messaging see aws.Config.CredentialsChainVerboseErrors

Where saw is an alias: alias saw='docker run --rm -it -v ~/.aws:/home/.aws tbrock/saw:v0.2.2'

I tried the fix you suggested in another reported issue about changing the mapping of the credentials file, but that doesn't solve my problem as I'm not depending on that file here.

The current credentials file approach works, but I have to login repeatedly and update my credentials file with the latest values which is a pain.

[geowa4]

I think the problem is with the Go SDK for AWS. I have a similar problem with Terraform and Terragrunt.

[khuongduybui]

any update?