Fix membership fees not being automatically applied

coin/billing/models.py

@@ -726,13 +726,13 @@ def bill_changed(sender, instance, created, **kwargs):
 
 @receiver(post_save, sender=MembershipFee)
 @disable_for_loaddata
-def fee_changed(sender, instance, created, **kwargs):
+def membershipfee_changed(sender, instance, created, **kwargs):
     if created and instance.member is not None:
         update_accounting_for_member(instance.member)
 
 @receiver(post_save, sender=Donation)
 @disable_for_loaddata
-def fee_changed(sender, instance, created, **kwargs):
+def donation_changed(sender, instance, created, **kwargs):
     if created and instance.member is not None:
         update_accounting_for_member(instance.member)