## 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"
        }
    ]
}
```
if response.status_code >= 400:
            LOG.debug('Error response from CloudFormation (%s) %s %s: %s' %
                      (response.status_code, method, path, response.content))
        if response._content:
            aws_stack.fix_account_id_in_arns(response)
    def _list_stack_names(self):
        client = aws_stack.connect_to_service('cloudformation')
        stacks = client.list_stacks()['StackSummaries']
        stack_names = []
        for stack in stacks:
            status = stack['StackStatus']
            if 'FAILED' in status or 'DELETE' in status:
                continue
            stack_names.append(stack['StackName'])
        return stack_names
UPDATE_CLOUDFORMATION = ProxyListenerCloudFormation()