1. Enable region specific client factory (https://github.com/awslabs/aws-config-rdklib/pull/21)
2. add cloudformation output for rdklib layer arn (https://github.com/awslabs/aws-config-rdklib/pull/30)
3. Added is_applicable flag which allows the user to determine if a resource experiences a "Delete" event (https://github.com/awslabs/aws-config-rdklib/pull/32)
4. update the application in AWS Serverless Application Repository with latest dependencies like boto3.