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`.
return re.sub(r'^%s/(.*)$' % config.TMP_FOLDER,
                    r'%s/\1' % config.HOST_TMP_FOLDER, path)
class LambdaExecutorLocal(LambdaExecutor):
    def _execute(self, func_arn, func_details, event, context=None, version=None):
        lambda_cwd = func_details.cwd
        environment = func_details.envvars.copy()
        
        queue = Queue()
        lambda_function = func_details.function(version)
        def do_execute():
            
            if lambda_cwd:
                os.chdir(lambda_cwd)
            if environment:
                os.environ.update(environment)
            result = lambda_function(event, context)
            queue.put(result)
        process = Process(target=do_execute)
        with CaptureOutput() as c:
            process.run()
        result = queue.get()
        
        log_output = ''
        for stream in (c.stdout(), c.stderr()):
            if stream:
                log_output += ('\n' if log_output else '') + stream
        return result, log_output
    def execute_java_lambda(self, event, context, handler, main_file):