Fix typo in method name call

Author: rennerocha

thebook/members/management/commands/create_receivable_fees_for_next_period.py

@@ -8,7 +8,7 @@ class Command(BaseCommand):
     help = "Create receivable fees for next period"
 
     def handle(self, *args, **options):
-        ReceivableFee.objects.create_for_next_iperiod()
+        ReceivableFee.objects.create_for_next_period()
 
         self.stdout.write(
             self.style.SUCCESS("Successfully create d receivable fees for next period")