Updated Notification model to use Float(asdecimal=False) for rate_mutliplier.

Added test with multiple rows for a month.

tests/app/conftest.py

@@ -444,7 +444,8 @@ def sample_notification(
     api_key_id=None,
     key_type=KEY_TYPE_NORMAL,
     sent_by=None,
-    client_reference=None
+    client_reference=None,
+    rate_multiplier=1.0
 ):
     if created_at is None:
         created_at = datetime.utcnow()
@@ -481,7 +482,8 @@ def sample_notification(
         'key_type': key_type,
         'sent_by': sent_by,
         'updated_at': created_at if status in NOTIFICATION_STATUS_TYPES_COMPLETED else None,
-        'client_reference': client_reference
+        'client_reference': client_reference,
+        'rate_multiplier': rate_multiplier
     }
     if job_row_number is not None:
         data['job_row_number'] = job_row_number