I am using the **latest** localstack docker image to test aws s3, lambda and cloudformation locally. s3 and lambda seems to be working fine but when I call cloudformation **create-stack** api it gives me a 502 BadGateway error. This is the command I am using

`aws cloudformation create-stack \
  --template-body template.yaml \
  --stack-name cfn-test \
  --parameters ParameterKey=BucketPrefix,ParameterValue=demo-bucket \
  --endpoint-url=http://localhost:4581`

This is the error I get:
`An error occurred (502) when calling the CreateStack operation (reached max retries: 4): Bad Gateway`

From docker logs I got the following error
`2019-12-31T22:12:09:ERROR:localstack.services.generic_proxy: Error forwarding request: 'str' object has no attribute 'get' Traceback (most recent call last):
  File "/opt/code/localstack/localstack/services/generic_proxy.py", line 242, in forward
    path=path, data=data, headers=forward_headers)
  File "/opt/code/localstack/localstack/services/cloudformation/cloudformation_listener.py", line 164, in forward_request
    modified_request = transform_template(req_data)
  File "/opt/code/localstack/localstack/services/cloudformation/cloudformation_listener.py", line 83, in transform_template
    if parsed.get('Transform') == 'AWS::Serverless-2016-10-31':
AttributeError: 'str' object has no attribute 'get'`

Although, when I try the **list-stacks** api it seems to be working fine
`aws --endpoint-url=http://localhost:4581 cloudformation list-stacks`

`{
    "StackSummaries": []
}`

`2019-12-31 22:10:51,865:API: 127.0.0.1 - - [31/Dec/2019 22:10:51] "GET / HTTP/1.1" 200 -`

I could not find a solution in any of the past issues or anywhere on the internet. Please assist
except Exception as e:
        LOG.warning('Error calling %s with params: %s for resource: %s' % (function, params, resource))
        raise e
    
    if resource_type == 'ApiGateway::Method':
        integration = resource_props.get('Integration')
        if integration:
            api_id = resolve_refs_recursively(stack_name, resource_props['RestApiId'], resources)
            res_id = resolve_refs_recursively(stack_name, resource_props['ResourceId'], resources)
            uri = integration.get('Uri')
            if uri:
                uri = resolve_refs_recursively(stack_name, uri, resources)
                aws_stack.connect_to_service('apigateway').put_integration(
                    restApiId=api_id, resourceId=res_id,
                    httpMethod=resource_props['HttpMethod'], type=integration['Type'],
                    integrationHttpMethod=integration['IntegrationHttpMethod'], uri=uri)
    elif resource_type == 'SNS::Topic':
        subscriptions = resource_props.get('Subscription', [])
        for subscription in subscriptions:
            endpoint = resolve_refs_recursively(stack_name, subscription['Endpoint'], resources)
            topic_arn = retrieve_topic_arn(params['Name'])
            aws_stack.connect_to_service('sns').subscribe(
                TopicArn=topic_arn, Protocol=subscription['Protocol'], Endpoint=endpoint)
    elif resource_type == 'S3::Bucket':
        tags = resource_props.get('Tags')
        if tags:
            aws_stack.connect_to_service('s3').put_bucket_tagging(
                Bucket=params['Bucket'], Tagging={'TagSet': tags})
    return result
def deploy_template(template, stack_name):