[temp] add solidus_legacy_promotions as backend dependency

In the future, the admin views for legacy promotions will live in the
solidus_legacy_promotions gems. This is just to see if we get a green
build.

backend/lib/solidus_backend.rb

@@ -1,3 +1,4 @@
 # frozen_string_literal: true
 
 require 'spree_backend'
+require 'solidus_legacy_promotions'

backend/solidus_backend.gemspec

@@ -25,6 +25,7 @@ Gem::Specification.new do |s|
 
   s.add_dependency 'solidus_api', s.version
   s.add_dependency 'solidus_core', s.version
+  s.add_dependency 'solidus_legacy_promotions', s.version
 
   s.add_dependency 'font-awesome-rails', '~> 4.0'
   s.add_dependency 'jbuilder', '~> 2.8'

backend/spec/spec_helper.rb

@@ -47,6 +47,8 @@
 require 'spree/testing_support/blacklist_urls'
 require 'spree/testing_support/silence_deprecations'
 
+require 'solidus_legacy_promotions/testing_support/factory_bot'
+
 require 'capybara-screenshot/rspec'
 Capybara.save_path = ENV['CIRCLE_ARTIFACTS'] if ENV['CIRCLE_ARTIFACTS']
 Capybara.exact = true
@@ -79,6 +81,7 @@
 
 ActiveJob::Base.queue_adapter = :test
 
+SolidusLegacyPromotions::TestingSupport::FactoryBot.add_definitions!
 Spree::TestingSupport::FactoryBot.add_paths_and_load!
 
 RSpec.configure do |config|