Error in SwaggerUI when POSTing arrays

When I create a POST handler with the following signature:

```swift
func addContacts(contacts: [Contact], completion: @escaping ([Contact]?, RequestError?) -> Void) {
completion(contacts, nil)
}
```

I get the following error in SwaggerUI when clicking on the **Try it out** button for the API:

```
Errors

Resolver error at paths./contacts/.post.parameters.0.schema.$ref
Could not resolve reference because of: Could not resolve pointer: /definitions/Array does not exist in document
```