Added wrap_params to BaseController, to make API work with Backbone

I am not sure about it, as you use `paramRoot` in [spree-marionette](https://github.com/radar/spree-marionette/blob/master/app/assets/javascripts/spree/models/line_items.js#L14).
But for me `wrap_params` shouldn't affect anything, and for me it's more convenient to add it.