## Issue description
When creating a CloudFormation stack, the `CreationDate` is always `2011-05-23T15:47:44Z`

## Steps to reproduce
1. Prepare a CloudFormation file, for example
```yml
AWSTemplateFormatVersion: 2010-09-09
Description: My Stack
Resources:
  LambdaCodeBucket:
    Type: AWS::S3::Bucket
    Properties:
      BucketName: my-bucket
```
2. Create a new stack based on this file, I used the command:
```bash
awslocal cloudformation create-stack --stack-name gch --template-body file://stack.yml
```
3. List all the created stacks and confirm the `CreationDate` is not a present date
```
awslocal cloudformation list-stacks
```
```
{
    "StackSummaries": [
        {
            "StackId": "arn:aws:cloudformation:us-east-1:000000000000:stack/stack/27187f13-a645-40a0-8788-62d502358216",
            "StackName": "stack",
            "TemplateDescription": "My Stack",
            "CreationTime": "2011-05-23T15:47:44Z",
            "StackStatus": "CREATE_COMPLETE"
        }
    ]
}
```
return
        record = {
            'eventID': '1',
            'eventVersion': '1.0',
            'dynamodb': {
                'StreamViewType': 'NEW_AND_OLD_IMAGES',
                'SizeBytes': -1
            },
            'awsRegion': aws_stack.get_region(),
            'eventSource': 'aws:dynamodb'
        }
        records = [record]
        if action == '%s.UpdateItem' % ACTION_PREFIX:
            if response.status_code == 200:
                updated_item = find_existing_item(data)
                if not updated_item:
                    return
                record['eventName'] = 'MODIFY'
                record['dynamodb']['Keys'] = data['Key']
                record['dynamodb']['OldImage'] = self._thread_local('existing_item')
                record['dynamodb']['NewImage'] = updated_item
                record['dynamodb']['SizeBytes'] = len(json.dumps(updated_item))
        elif action == '%s.BatchWriteItem' % ACTION_PREFIX:
            records = self.prepare_batch_write_item_records(record, data)
        elif action == '%s.TransactWriteItems' % ACTION_PREFIX:
            records = self.prepare_transact_write_item_records(record, data)
        elif action == '%s.PutItem' % ACTION_PREFIX:
            if response.status_code == 200:
                existing_item = self._thread_local('existing_item')
                record['eventName'] = 'INSERT' if not existing_item else 'MODIFY'