lib/plugins/aws/provider/awsProvider.js/AwsProvider/getAccountInfo
class AwsProvider:  getAccountInfo() {
    return this.request('STS', 'getCallerIdentity', {}).then(result => {
      const arn = result.Arn;
      const accountId = result.Account;
      const partition = _.nth(_.split(arn, ':'), 1); // ex: arn:aws:iam:acctId:user/xyz
      return {
        accountId,
        partition,
        arn: result.Arn,
        userId: result.UserId,
      };
    });
  }