Fix syntax for nil properties

spec/factories/address_factory.rb

@@ -25,7 +25,7 @@ FactoryBot.define do
       firstname { FFaker::Name.first_name }
       lastname { FFaker::Name.last_name }
       address1 { FFaker::Address.street_address }
-      address2 nil
+      address2 { nil }
       phone { FFaker::PhoneNumber.phone_number }
     end
   end

spec/factories/line_item_factory.rb

@@ -11,7 +11,7 @@ FactoryBot.define do
   factory :line_item_with_shipment, parent: :line_item do
     transient do
       shipping_fee { 3 }
-      shipping_method nil
+      shipping_method { nil }
     end
 
     after(:build) do |line_item, evaluator|

spec/factories/order_cycle_factory.rb

@@ -106,8 +106,8 @@ FactoryBot.define do
   end
 
   factory :undated_order_cycle, parent: :simple_order_cycle do
-    orders_open_at  nil
-    orders_close_at nil
+    orders_open_at { nil }
+    orders_close_at { nil }
   end
 
   factory :upcoming_order_cycle, parent: :simple_order_cycle do

spec/factories/order_factory.rb

@@ -8,7 +8,7 @@ FactoryBot.define do
 
     user
     bill_address
-    completed_at nil
+    completed_at { nil }
     email { user.email }
 
     factory :order_with_totals do

spec/factories/product_factory.rb

@@ -8,7 +8,7 @@ FactoryBot.define do
     cost_price { 17.00 }
     sku { 'ABC' }
     available_on { 1.year.ago }
-    deleted_at nil
+    deleted_at { nil }
 
     supplier { Enterprise.is_primary_producer.first || FactoryBot.create(:supplier_enterprise) }
     primary_taxon { Spree::Taxon.first || FactoryBot.create(:taxon) }
@@ -69,7 +69,7 @@ FactoryBot.define do
     transient do
       tax_rate_amount { 0 }
       tax_rate_name { "" }
-      zone nil
+      zone { nil }
     end
 
     tax_category { create(:tax_category) }

spec/factories/taxon_factory.rb

@@ -4,6 +4,6 @@ FactoryBot.define do
   factory :taxon, class: Spree::Taxon do
     name { 'Ruby on Rails' }
     taxonomy
-    parent_id nil
+    parent_id { nil }
   end
 end