Correct the Wisper listeners

app/listeners/campaign_listener.rb

@@ -3,7 +3,7 @@
 # License: AGPL-3.0-or-later WITH WTO-AP-3.0-or-later
 # Full license explanation at https://github.com/houdiniproject/houdini/blob/master/LICENSE
 class CampaignListener < ApplicationListener
-    def campaign_create(campaign)
+    def self.campaign_create(campaign)
       if campaign.child_campaign?
         CampaignCreationFederatedEmailJob.perform_later(campaign)
       else

app/listeners/credit_card_payment_listener.rb

@@ -3,32 +3,32 @@
 # License: AGPL-3.0-or-later WITH WTO-AP-3.0-or-later
 # Full license explanation at https://github.com/houdiniproject/houdini/blob/master/LICENSE
 class CreditCardPaymentListener < ApplicationListener
-    def donation_create(donation, locale, user=nil)
+    def self.donation_create(donation, locale, user=nil)
       if donation.payment_provider == :credit_card
         PaymentNotificationEmailDonorJob.perform_later donation, locale
         PaymentNotificationEmailNonprofitJob.perform_later donation, user
       end
     end
 
-    def recurring_donation_create(donation, locale, user=nil)
+    def self.recurring_donation_create(donation, locale, user=nil)
       if donation.payment_provider == :credit_card
         PaymentNotificationEmailDonorJob.perform_later donation, locale
         PaymentNotificationEmailNonprofitJob.perform_later donation, user
       end
     end
 
-    def refund_create(refund)
+    def self.refund_create(refund)
       RefundNotificationJob.perform_later refund
     end
 
-    def recurring_donation_payment_succeeded(donation, locale, user=nil)
+    def self.recurring_donation_payment_succeeded(donation, locale, user=nil)
       if donation.payment_provider == :credit_card
         PaymentNotificationEmailDonorJob.perform_later donation, locale
         PaymentNotificationEmailNonprofitJob.perform_later donation, user
       end
     end
 
-    def recurring_donation_payment_failed(donation, locale)
+    def self.recurring_donation_payment_failed(donation, locale)
       FailedRecurringDonationPaymentDonorEmailJob.perform_later(donation)
       if (donation.recurring_donation.n_failures >= 3)
         FailedRecurringDonationPaymentNonprofitEmailJob.perform_later(donation)

app/listeners/sepa_payment_listener.rb

@@ -3,7 +3,7 @@
 # License: AGPL-3.0-or-later WITH WTO-AP-3.0-or-later
 # Full license explanation at https://github.com/houdiniproject/houdini/blob/master/LICENSE
 class SepaPaymentListener < ApplicationListener
-    def donation_create(donation)
+    def self.donation_create(donation)
       if donation.payment_provider == :sepa
         DirectDebitCreateNotifyNonprofitJob.perform_later(donation.id)
         DirectDebitCreateNotifyDonorJob.perform_later donation.id, locale

app/listeners/ticket_listener.rb

@@ -3,7 +3,7 @@
 # License: AGPL-3.0-or-later WITH WTO-AP-3.0-or-later
 # Full license explanation at https://github.com/houdiniproject/houdini/blob/master/LICENSE
 class TicketListener < ApplicationListener
-    def ticket_create(tickets, charge, user=nil)
+    def self.ticket_create(tickets, charge, user=nil)
         TicketMailer.followup(tickets.map{|i| i.id}, charge && charge.id).deliver_later
         TicketMailer.receipt_admin(tickets.map{|i| i.id}, user && user.id).deliver_later
     end

app/listeners/wemove_listener.rb

@@ -3,15 +3,15 @@
 # License: AGPL-3.0-or-later WITH WTO-AP-3.0-or-later
 # Full license explanation at https://github.com/houdiniproject/houdini/blob/master/LICENSE
 class WemoveListener < ApplicationListener
-    def donation_create(donation)
+    def self.donation_create(donation)
       WeMoveExecuteForDonationsJob.perform_later(donation)
     end
 
-    def offsite_donation_create(donation)
+    def self.offsite_donation_create(donation)
       WeMoveExecuteForDonationsJob.perform_later(donation)
     end
 
-    def recurring_donation_create(donation)
+    def self.recurring_donation_create(donation)
       WeMoveExecuteForDonationsJob.perform_later(donation)
     end
 end