SmokeAWSCredentials in README.md

[fabianfett]

import SmokeAWSCredentials
...

    guard let credentialsProvider = AwsContainerRotatingCredentials.getCredentials(fromEnvironment: environment) else {
        return Log.error("Unable to obtain credentials from the container environment.")
    }

The README.md has a section about ** Step 4: Instantiate the AWS client for production** as seen above. I can't find bespoken library neither in the master nor in the swift_5_nio_2 branch. Also I can't find AwsContainerRotatingCredentials. Is StaticCredentials from SmokeAWSCore therefore the way to go? If so give me a thumbs up, I will open a PR to update the documentation.

[tachyonics]

It is in a separate repository

• https://github.com/amzn/smoke-aws-credentials

The README can probably be made clearer to avoid this understandable confusion if you'd like to open a PR. Thanks!