Add payment list view

Relates to #44

members/models.py

@@ -32,21 +32,8 @@ class Payment(models.Model):
     '''
     date = models.DateTimeField(default=datetime.fromtimestamp(0))
     source = models.CharField(max_length=255)
-    first_name = models.CharField(max_length=255)
-    last_name = models.CharField(max_length=255)
-    email = models.EmailField(max_length=255)
-    member = models.ForeignKey('Member', on_delete=models.SET_NULL, blank=True, null=True)
 
-    def get_dict(self):
-        return {
-            'id': self.id,
-            'date': date2str(self.date),
-            'source': self.source,
-            'first_name': self.first_name,
-            'last_name': self.last_name,
-            'email': self.email,
-            'member': self.member.get_dict() if self.member else {}
-        }
+    member = models.ForeignKey('Member', on_delete=models.SET_NULL, blank=True, null=True)
 
 
 class Member(BaseMember):