Set cost in Shipment#add_shipping_method
Set cost in Shipment#add_shipping_method

Running into weird total issues after https://github.com/spree/spree/commit/a7f16ac85ee7b250341eeb131a518922d931dd3d
See failing spec in https://github.com/spree/spree-adyen/pull/3

Hates/spree,Hates/spree,Hates/spree,Hates/spree,bjornlinder/Spree,bjornlinder/Spree,bjornlinder/Spree