code: func NewAuth(accessKey, secretKey, token string) Auth {
  	return &staticAuth{
  		staticCreds: &SigningKey{
  			AccessKeyId:     accessKey,
  			SecretAccessKey: secretKey,
  			SessionToken:    token,
  		},
  	}
  }
docs: // NewAuth creates return an auth object that uses static
  // credentials which do not automatically renew.