[auth] Account Page should have Order History

[hhff]

[triptec]

from gitter: basically we need to add has_many :orders to the user serializer and display the orders on the /account route, provided by spree-ember-auth but I'd like to make them async instead of side-loaded because I don't want every request of the user to come with a huge chunk of orders if you don't need them i also haven't verified whether Spree automatically associates the current_order with the current_user when you a) login with a current order active, or b) create a new order while being logged in

[hhff]

:+1: