Add support for datadog's lambda extension for sending metrics
https://docs.datadoghq.com/serverless/datadog_lambda_library/extension
arn:aws:lambda:<AWS_REGION>:464622532012:layer:Datadog-Python27:23
arn:aws:lambda:<AWS_REGION>:464622532012:layer:Datadog-Python36:23
arn:aws:lambda:<AWS_REGION>:464622532012:layer:Datadog-Python37:23
arn:aws:lambda:<AWS_REGION>:464622532012:layer:Datadog-Python38:23
arn:aws-us-gov:lambda:us-gov-<AWS_REGION>:002406178527:layer:Datadog-Python27:23
arn:aws-us-gov:lambda:us-gov-<AWS_REGION>:002406178527:layer:Datadog-Python36:23
arn:aws-us-gov:lambda:us-gov-<AWS_REGION>:002406178527:layer:Datadog-Python37:23
arn:aws-us-gov:lambda:us-gov-<AWS_REGION>:002406178527:layer:Datadog-Python38:23