provision aurora-serverless and lambda function using AWS CDK.
$ export AWS_PROFILE=xxx
$ yarn run cdk deploy MyAppNetwork
$ yarn run cdk deploy MyAppDatabase
# need to enable data api manually by using cli.
$ aws rds modify-db-cluster \
--db-cluster-identifier [sample-cluster] \
--enable-http-endpoint
# NOTE: need to deploy each function one by one.
# when one function needs fixed, this reduces affect to other functions.
$ yarn run cdk deploy SampleFunction