Allow passing class string instead of transformer instance

[jodiedunlop]

The transform() collection() and item() methods, take an optional transformer instance as the second method. When omitted, the transformer resolver is used to try and find a matching transformer and instantiate it via the laravel app container.

It would be nice if you could pass MyTransformer::class (string) as the second argument, meaning that it should be instantiated via laravel's app container.

public function index()
{
    return Smokescreen::transform(User::all(), UserTransformer::class);
}

[lachlankrautz]

Implemented in 2.0.0