LoadSwaggerFromURIFunc is not called for eternal reference loading via loadSingleElementFromURI()

[ghost]

I'm attempting to use the LoadSwaggerFromURIFunc() to allow us to stub out the URI access and I've found that when references are required for a single element (apparently when there is no # in the path) the helper func is not called and the URI is accessed directly.

[fenollp]

Indeed, the call should be attempted instead of going straight for readURL.

I am not sure how you'd prefer this to work? SwaggerLoader.LoadSwaggerFromURIFunc func(loader *SwaggerLoader, url *url.URL) (*Swagger, error) is probably too weak a prototype to handle "single element URIs".

[fenollp]

Thanks to #316 you can now achieve what you want with (*SwaggerLoader).ReadFromURIFunc :)