Create a new instance of `LoaderType`

```js
var LoaderType = require('loader-cache');
var loaders = new LoaderType();
```
@api public
function LoaderType(options, fn) {
  if (!(this instanceof LoaderType)) {
    return new LoaderType(options);
  }
  LoaderStack.call(this);
  this.iterator = new Iterator(options, fn);
}