From Aurora Serverless's document, there are 3 ways to create an Aurora serverless DB cluster: AWS management console, CLI, and RDS API. (<https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/aurora-serverless.create.html>) 

Form my understanding, one would use `EngineMode` in the RDS API to create Aurora Serverless, but this property is not available in `AWS::RDS::DBCluster` yet (<https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-rds-dbcluster.html>). 

Would it be possible to create an Aurora Serverless Cluster from cloudformation? Any advice would be appreciated!