## 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"
        }
    ]
}
```
import re
import os
import json
import uuid
import boto3
import logging
from requests.models import Request, Response
from six.moves.urllib import parse as urlparse
from samtranslator.translator.transform import transform as transform_sam
from localstack.utils.aws import aws_stack
from localstack.utils.common import to_str, obj_to_xml, safe_requests, run_safe
from localstack.utils.analytics import event_publisher
from localstack.utils.cloudformation import template_deployer
from localstack.services.generic_proxy import ProxyListener
XMLNS_CLOUDFORMATION = 'http://cloudformation.amazonaws.com/doc/2010-05-15/'
LOG = logging.getLogger(__name__)
def error_response(message, code=400, error_type='ValidationError'):
    response = Response()
    response.status_code = code
    response.headers['x-amzn-errortype'] = error_type
    response._content = """<ErrorResponse xmlns="%s">
          <Error>
            <Type>Sender</Type>
            <Code>%s</Code>
            <Message>%s</Message>
          </Error>
          <RequestId>%s</RequestId>
        </ErrorResponse>""" % (XMLNS_CLOUDFORMATION, error_type, message, uuid.uuid4())
    return response
def make_response(operation_name, content='', code=200):