## 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"
        }
    ]
}
```
self._table_ttl_map = {}
    def forward_request(self, method, path, data, headers):
        if path.startswith('/shell') or method == 'GET':
            if path == '/shell':
                headers = {'Refresh': '0; url=%s/shell/' % config.TEST_DYNAMODB_URL}
                return aws_responses.requests_response('', headers=headers)
            return True
        if method == 'OPTIONS':
            return 200
        data = json.loads(to_str(data))
        ddb_client = aws_stack.connect_to_service('dynamodb')
        action = headers.get('X-Amz-Target')
        if random.random() < config.DYNAMODB_ERROR_PROBABILITY:
            throttled = ['%s.%s' % (ACTION_PREFIX, a) for a in THROTTLED_ACTIONS]
            if action in throttled:
                return error_response_throughput()
        ProxyListenerDynamoDB.thread_local.existing_item = None
        if action == '%s.CreateTable' % ACTION_PREFIX:
            
            table_names = ddb_client.list_tables()['TableNames']
            if to_str(data['TableName']) in table_names:
                return 200
        elif action in ('%s.PutItem' % ACTION_PREFIX, '%s.UpdateItem' % ACTION_PREFIX, '%s.DeleteItem' % ACTION_PREFIX):
            
            
            try:
                ProxyListenerDynamoDB.thread_local.existing_item = find_existing_item(data)