The following example `serverless.yml` fails to deploy on localstack:

```yaml
service: "localtest"

provider:
  name: "aws"
  runtime: "nodejs10.x"

functions:
  hello:
    handler: "handler.hello"
    
resources:
  Resources:
    ApiGatewayRestApi:
      Type: "AWS::ApiGateway::RestApi"
      Properties:
        Name: "${self:provider.stage}-${self:service}"
    GatewayResponseDefault400:
      Type: "AWS::ApiGateway::GatewayResponse"
      Properties:
        RestApiId:
          Ref: "ApiGatewayRestApi"
        ResponseType: "DEFAULT_4XX"
        ResponseTemplates:
          application/json: '{"errors":[{"message":"Custom text."}]}'
    GatewayResponseUnauthorized:
      Type: "AWS::ApiGateway::GatewayResponse"
      Properties:
        RestApiId:
          Ref: "ApiGatewayRestApi"
        ResponseType: "UNAUTHORIZED"
        ResponseTemplates:
          application/json: '{"errors":[{"message":"Custom text!", "extra":"Some extra info"}]}'
    GatewayResponseDefault500:
      Type: "AWS::ApiGateway::GatewayResponse"
      Properties:
        RestApiId:
          Ref: "ApiGatewayRestApi"
        ResponseType: "DEFAULT_5XX"
        ResponseTemplates:
          application/json: '{"errors":[{"message":$context.error.messageString}]}'
    GatewayResponseIntegrationTimeout:
      Type: "AWS::ApiGateway::GatewayResponse"
      Properties:
        RestApiId:
          Ref: "ApiGatewayRestApi"
        ResponseType: "INTEGRATION_TIMEOUT"
        ResponseTemplates:
          application/json: '{"errors":[{"message":$context.error.messageString}]}'

plugins:
- "serverless-localstack"

custom:
  localstack:
    stages:
      - "local"
```

The error on the localstack end is `Exception: CloudFormation deployment for resource type ApiGateway::GatewayResponse not yet implemented`.
if _type == bool:
            return _obj in ['True', 'true', True]
        if _type == str:
            return str(_obj)
        if _type == int:
            return int(_obj)
        return _obj
    def fix_types(o, **kwargs):
        if isinstance(o, dict):
            for k, v in o.items():
                if k in attr_names:
                    o[k] = cast(v, types[k])
        return o
    result = common.recurse_object(params, fix_types)
    return result
def deploy_resource(resource_id, resources, stack_name):
    resource = resources[resource_id]
    resource_type = get_resource_type(resource)
    func_details = RESOURCE_TO_FUNCTION.get(resource_type)
    if not func_details:
        LOG.warning('Resource type not yet implemented: %s' % resource_type)
        return
    LOG.debug('Deploying resource type "%s" id "%s"' % (resource_type, resource_id))
    func_details = func_details[ACTION_CREATE]
    func_details = func_details if isinstance(func_details, list) else [func_details]
    results = []
    for func in func_details:
        client = get_client(resource, func)