Change the base.rb active_shipping calculator to only do rate calculations for the stock_location
that is represented by the passed in object. We are dealing with Spree::Shipment and Spree::Stock::Package
objects only.

In researching this issue, it seems we are passing a Spree::Shipment object whenever promotion_adjustments
is called when adding items to the cart and on checkout, we are passing the Spree::Stock::Package object.

The crux of the change is at line 160 where I am limiting calculations to the object.stock_location_id
Merge pull request #87 from rterbush/master

Change the base.rb active_shipping calculator to only do rate calculations for the stock_location
Allow order object to be passed in. We have shipping_method.id which
is required.
Merge pull request #89 from rterbush/splitship-order-master

Allow Spree::Order object to be passed in
remove raise ShippingError from compute, fix #90

commit 5150d1fd80f44e69464eccd9fd034657933d1d12 taken from 1-3-stable
Merge pull request #92 from rterbush/master

remove raise ShippingError from compute, fix #90
Get rspec to at least run...

Help welcome to fix these now..
Merge pull request #94 from rterbush/tests

Get rspec to at least run...