## 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"
        }
    ]
}
```
template_body = get_template_body(req_data)
    parsed = template_deployer.parse_template(template_body)
    policy_map = {
        
        'dummy': 'entry'
        
    }
    class MockPolicyLoader(object):
        def load(self):
            return policy_map
    if parsed.get('Transform') == 'AWS::Serverless-2016-10-31':
        
        region_before = os.environ.get('AWS_DEFAULT_REGION')
        if boto3.session.Session().region_name is None:
            os.environ['AWS_DEFAULT_REGION'] = aws_stack.get_region()
        try:
            transformed = transform_sam(parsed, {}, MockPolicyLoader())
            return transformed
        finally:
            os.environ.pop('AWS_DEFAULT_REGION', None)
            if region_before is not None:
                os.environ['AWS_DEFAULT_REGION'] = region_before
def get_template_body(req_data):
    body = req_data.get('TemplateBody')
    if body:
        return body
    url = req_data.get('TemplateURL')
    if url:
        response = run_safe(lambda: safe_requests.get(url, verify=False))