With the following serverless.yml file:
```yml
service: localtest

provider:
  name: aws
  runtime: nodejs10.x

functions:
  hello:
    handler: handler.hello
    events:
    - stream:
        type: dynamodb
        arn:
          Fn::GetAtt: [fooTable, StreamArn]

resources:
  Resources:
    fooTable:
      Type: AWS::DynamoDB::Table
      Properties:
        TableName: fooTable
        AttributeDefinitions:
          - AttributeName: foo
            AttributeType: S
        KeySchema:
          - AttributeName: foo
            KeyType: HASH
        ProvisionedThroughput:
          ReadCapacityUnits: 1
          WriteCapacityUnits: 1
        StreamSpecification:
          StreamViewType: NEW_AND_OLD_IMAGES

plugins:
- "serverless-localstack"

custom:
  localstack:
    stages:
      - "local"
```
It fails with a generic error (500) on the deployment end and with `:ERROR:localstack.services.cloudformation.cloudformation_starter: Unable to parse and create resource "HelloEventSourceMappingDynamodbFooTable": 'NoneType' object has no attribute 'function_arn'` on the localstack end.
It deploys fine to AWS.
""" Helper class to convert JSON documents with datetime, decimals, or bytes. """
    def default(self, o):
        if isinstance(o, decimal.Decimal):
            if o % 1 > 0:
                return float(o)
            else:
                return int(o)
        if isinstance(o, datetime):
            return str(o)
        if isinstance(o, six.binary_type):
            return to_str(o)
        try:
            return super(CustomEncoder, self).default(o)
        except Exception:
            return None
class ShellCommandThread(FuncThread):