Swagger definition with a reference instead of a type

[guisrx]

https://github.com/kogosoftwarellc/open-api/blob/6463d50555e6faf4875771839d3edbfe1232214b/packages/openapi-types/index.ts#L545

If you have a swagger definition like this:

"PagesRef": {
    "type": "array",
    "items": {
      "$ref": "#/definitions/PagesMemberRef"
    }
}

You can't use OpenAPIV2.Document as type is a mandatory attribute.

[jsdevel]

@guisrx please submit a PR