Disable Rubocop Rails/Exit locally

This cop makes a lot of sense for the part of the app that runs
permanently, but both of these cases are instances where the code being
aborted is run as a one-off from the command line.

Author: mamhoff

admin/lib/solidus_admin/testing_support/admin_assets.rb

@@ -3,7 +3,9 @@
 RSpec.configure do |config|
   config.when_first_matching_example_defined(solidus_admin: true) do
     config.before(:suite) do
-      system('bin/rails solidus_admin:tailwindcss:build') or abort 'Failed to build Tailwind CSS'
+      # rubocop:disable Rails/Exit
+      system("bin/rails solidus_admin:tailwindcss:build") or abort "Failed to build Tailwind CSS"
+      # rubocop:enable Rails/Exit
       Rails.application.precompiled_assets
     end
   end

core/lib/generators/solidus/install/app_templates/authentication/existing.rb

@@ -4,7 +4,9 @@
   user_class.classify.constantize
 rescue NameError
   say_status :error, "Can't find an existing user class named #{user_class.classify}, plese set up one before using this authentication option.", :red
+  # rubocop:disable Rails/Exit
   abort
+  # rubocop:enable Rails/Exit
 end
 
 generate "spree:custom_user #{user_class.shellescape}"