Hi

I have issues creating sns subscriptions through Cloudformation. If I attempt to include a `AWS::SNS::Subscription` resource in a Cloudformation template and run `create-stack` then I get a 500 Internal Server error. The full template:

```
AWSTemplateFormatVersion: '2010-09-09'
Description: 'Test'
Resources:
  MySnsTopic:
    Type: AWS::SNS::Topic
    Properties:
      TopicName: MySnsTopic
  MySnsTopicSubscription:
    Type: AWS::SNS::Subscription
    Properties:
      Protocol: sqs
      TopicArn: !Ref MySnsTopic
      Endpoint: !GetAtt
        - MySqsQueue
        - QueueArn
  MySqsQueue:
    Type: AWS::SQS::Queue
    Properties:
      QueueName: MySqsQueue
```

If I replace the references with hard-coded arns like this:

```
TopicArn: arn:aws:sns:eu-west-2:123456789012:MySnsTopic
Endpoint: arn:aws:sqs:elasticmq:000000000000:MySqsQueue
```

Then I get no errors but I get a warning:

`No moto Cloudformation support for AWS::SNS::Subscription`.

I can get around this issue by creating the subscription when creating the topic but the issue there is that I cannot add any attributes and in my case I need `RawMessageDelivery` set to true. So my questions are:

1. Is there no support to create `AWS::SNS::Subscription` resources through Cloudformation or am I doing something wrong?
2. If support is not there can I request it as a new feature?
3. Any suggestions on how I can work around this? I know I could do this through a script at startup but would like to not have any additional script steps other than deploying the Cloudformation stack.

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lambda_handler = generic_handler
    if runtime == LAMBDA_RUNTIME_JAVA8:
        
        
        
        
        lambda_handler, zip_file_content = get_java_handler(zip_file_content, handler_name, tmp_file)
        if is_jar_archive(zip_file_content):
            jar_tmp_file = '{working_dir}/{file_name}'.format(
                working_dir=lambda_cwd, file_name=LAMBDA_JAR_FILE_NAME)
            save_file(jar_tmp_file, zip_file_content)
    else:
        handler_file = get_handler_file_from_name(handler_name, runtime=runtime)
        handler_function = get_handler_function_from_name(handler_name, runtime=runtime)
        if not is_local_mount:
            
            if not is_zip_file(zip_file_content):
                raise ClientError(
                    'Uploaded Lambda code for runtime ({}) is not in Zip format'.format(runtime))
            unzip(tmp_file, lambda_cwd)
        main_file = '%s/%s' % (lambda_cwd, handler_file)
        if not os.path.exists(main_file):
            
            
            
            if not is_local_mount or not use_docker() or config.LAMBDA_REMOTE_DOCKER:
                file_list = run('cd %s; du -d 3 .' % lambda_cwd)
                config_debug = ('Config for local mount, docker, remote: "%s", "%s", "%s"' %
                    (is_local_mount, use_docker(), config.LAMBDA_REMOTE_DOCKER))