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`.
props = cloudformation_json['Properties']
        name = props['StageName']
        deployment_id = props.get('Id') or short_uid()
        description = props.get('Description') or ''
        return apigw_models.Deployment(deployment_id, name, description)
    @classmethod
    def Resource_create_from_cloudformation_json(cls, resource_name, cloudformation_json, region_name):
        props = cloudformation_json['Properties']
        region_name = props.get('Region') or aws_stack.get_region()
        path_part = props.get('PathPart')
        api_id = props.get('RestApiId')
        parent_id = props.get('ParentId')
        id = props.get('Id') or short_uid()
        return apigw_models.Resource(id, region_name, api_id, path_part, parent_id)
    @classmethod
    def Method_create_from_cloudformation_json(cls, resource_name, cloudformation_json, region_name):
        props = cloudformation_json['Properties']
        method_type = props.get('HttpMethod')
        authorization_type = props.get('AuthorizationType')
        return apigw_models.Method(method_type, authorization_type)
    apigw_models.RestAPI.create_from_cloudformation_json = RestAPI_create_from_cloudformation_json
    apigw_models.RestAPI.get_cfn_attribute = RestAPI_get_cfn_attribute
    apigw_models.Deployment.create_from_cloudformation_json = Deployment_create_from_cloudformation_json
    apigw_models.Resource.create_from_cloudformation_json = Resource_create_from_cloudformation_json
    apigw_models.Method.create_from_cloudformation_json = Method_create_from_cloudformation_json
    
    
    def describe_stack_resource(self):