Add payment list view

Relates to #44

members/admin.py

@@ -1,6 +1,7 @@
 from django.contrib import admin
-from members.models import Member, Request
+from members.models import Member, Request, Payment
 
 # Register your models here.
 admin.site.register(Member)
 admin.site.register(Request)
+admin.site.register(Payment)