Add organisation id to bu factory

spec/factories/bulk_upload.rb

@@ -9,6 +9,7 @@ FactoryBot.define do
     sequence(:filename) { |n| "bulk-upload-#{n}.csv" }
     needstype { 1 }
     rent_type_fix_status { BulkUpload.rent_type_fix_statuses.values.sample }
+    organisation_id { user.organisation_id }
 
     trait(:sales) do
       log_type { BulkUpload.log_types[:sales] }