Fix stock issue and update specs (now passing)

See: dcd5944a29

app/models/spree/stock_item.rb

@@ -6,7 +6,7 @@ module Spree
 
     belongs_to :stock_location, class_name: 'Spree::StockLocation'
     belongs_to :variant, class_name: 'Spree::Variant'
-    has_many :stock_movements, dependent: :destroy
+    has_many :stock_movements
 
     validates :stock_location, :variant, presence: true
     validates :variant_id, uniqueness: { scope: [:stock_location_id, :deleted_at] }

spec/models/spree/product_spec.rb

@@ -240,7 +240,7 @@ module Spree
       let(:variant) { product.master }
       let(:stock_item) { variant.stock_items.first }
 
-      xit "doesnt raise ReadOnlyRecord error" do
+      it "doesnt raise ReadOnlyRecord error" do
         Spree::StockMovement.create!(stock_item: stock_item, quantity: 1)
         expect { product.destroy }.not_to raise_error
       end

spec/models/spree/stock_item_spec.rb

@@ -106,7 +106,7 @@ RSpec.describe Spree::StockItem do
     context "with stock movements" do
       before { Spree::StockMovement.create(stock_item: subject, quantity: 1) }
 
-      xit "doesnt raise ReadOnlyRecord error" do
+      it "doesnt raise ReadOnlyRecord error" do
         expect { subject.destroy }.not_to raise_error
       end
     end