removes sending individual proposal notifications via email

app/mailers/mailer.rb

@@ -42,14 +42,6 @@ class Mailer < ApplicationMailer
     end
   end
 
-  def proposal_notification(notification, voter)
-    @notification = notification
-
-    with_user(voter) do
-      mail(to: voter.email, subject: @notification.title + ": " + @notification.proposal.title)
-    end
-  end
-
   def direct_message_for_receiver(direct_message)
     @direct_message = direct_message
     @receiver = @direct_message.receiver