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`.
for resource_id, resource in iteritems(resources):
        if is_deployable_resource(resource):
            if not is_deployed(resource_id, all_resources, stack_name):
                return False
    return True
def resources_to_deploy_next(resources, stack_name):
    result = {}
    for resource_id, resource in iteritems(resources):
        if should_be_deployed(resource_id, resources, stack_name):
            result[resource_id] = resource
    return result
def get_resource_dependencies(resource_id, resource, resources):
    result = {}
    dumped = json.dumps(common.json_safe(resource))
    for other_id, other in iteritems(resources):
        if resource != other:
            
            search1 = '{"Ref": "%s"}' % other_id
            search2 = '{"Fn::GetAtt": ["%s", ' % other_id
            if search1 in dumped or search2 in dumped:
                result[other_id] = other
            if other_id in resource.get('DependsOn', []):
                result[other_id] = other
    return result