Add humanize school subscription end

apps/payment/models.py

@@ -1,3 +1,5 @@
+import arrow
+
 from paymentwall import Pingback
 from polymorphic.models import PolymorphicModel
 
@@ -165,3 +167,7 @@ class SchoolPayment(Payment):
             discount = 0
         self.amount = month_price_sum - discount
         super().save(*args, **kwargs)
+
+    @property
+    def date_end_humanize(self):
+        return arrow.get(self.date_end).humanize(locale='ru')