Add nested documents to new budgetinvestments.

app/controllers/budgets/investments_controller.rb

@@ -49,6 +49,7 @@ module Budgets
 
     def create
       @investment.author = current_user
+      recover_documents_from_cache(@investment)
 
       if @investment.save
         Mailer.budget_investment_created(@investment).deliver_later
@@ -105,7 +106,8 @@ module Budgets
 
       def investment_params
         params.require(:budget_investment).permit(:title, :description, :external_url, :heading_id, :tag_list,
-                                                  :organization_name, :location, :terms_of_service)
+                                                  :organization_name, :location, :terms_of_service,
+                                                  documents_attributes: [:id, :title, :attachment, :cached_attachment, :user_id])
       end
 
       def load_ballot