feedback from dan

app/grants/models.py

@@ -278,8 +278,10 @@ def history_by_month(self):
         # returns [["", "Subscription Billing",  "New Subscriptions", "One-Time Contributions", "CLR Matching Funds"], ["December 2017", 5534, 2011, 0, 0], ["January 2018", 10396, 0 , 0, 0 ], ... for each monnth in which this grant has contribution history];
         CLR_PAYOUT_HANDLES = ['vs77bb', 'gitcoinbot', 'notscottmoore', 'owocki']
         month_to_contribution_numbers = {}
-        for sub in self.subscriptions.all():
-            for contrib in sub.subscription_contribution.filter(success=True):
+        subs = self.subscriptions.all().prefetch_related('subscription_contribution')
+        for sub in subs:
+            contribs = [sc for sc in sub.subscription_contribution.all() if sc.success]
+            for contrib in contribs:
                 #add all contributions
                 key = contrib.created_on.strftime("%Y/%m")
                 subkey = 'One-Time'