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`.
RESOURCE_TO_FUNCTION = {
    'S3::Bucket': {
        'create': {
            'function': 'create_bucket',
            'parameters': {
                'Bucket': ['BucketName', PLACEHOLDER_RESOURCE_NAME],
                'ACL': lambda params, **kwargs: convert_acl_cf_to_s3(params.get('AccessControl', 'PublicRead')),
                'CreateBucketConfiguration': lambda params, **kwargs: get_bucket_location_config()
            }
        }
    },
    'SQS::Queue': {
        'create': {
            'function': 'create_queue',
            'parameters': {
                'QueueName': ['QueueName', PLACEHOLDER_RESOURCE_NAME],
                'Attributes': lambda params, **kwargs: select_attributes(params,
                    ['DelaySeconds', 'MaximumMessageSize', 'MessageRetentionPeriod',
                     'VisibilityTimeout', 'RedrivePolicy']
                ),
                'tags': 'Tags'
            }
        }
    },
    'SNS::Topic': {
        'create': {
            'function': 'create_topic',
            'parameters': {
                'Name': 'TopicName',
                'Tags': 'Tags'