variable rename, travis config fix?

.travis.yml

@@ -31,9 +31,3 @@ before_install:
   pip install codecov
 after_success:
   codecov
-
-# Because Python 3.5 does not want to play nicely with current versions of Django
-matrix:
-  exclude:
-    - python: 3.5
-      env: DJANGO=1.8.7

djstripe/models.py

@@ -338,16 +338,16 @@ def attach_objects_hook(self, cls, data):
 
     # SYNC methods should be dropped in favor of the master sync infrastructure proposed
     def _sync_invoices(self, **kwargs):
-        for invoice in Invoice.api_list(customer=self.stripe_id, **kwargs):
-            Invoice.sync_from_stripe_data(invoice)
+        for stripe_invoice in Invoice.api_list(customer=self.stripe_id, **kwargs):
+            Invoice.sync_from_stripe_data(stripe_invoice)
 
     def _sync_charges(self, **kwargs):
-        for charge in Charge.api_list(customer=self.stripe_id, **kwargs):
-            Charge.sync_from_stripe_data(charge)
+        for stripe_charge in Charge.api_list(customer=self.stripe_id, **kwargs):
+            Charge.sync_from_stripe_data(stripe_charge)
 
     def _sync_subscriptions(self, **kwargs):
-        for subscription in Subscription.api_list(customer=self.stripe_id, **kwargs):
-            Subscription.sync_from_stripe_data(subscription)
+        for stripe_subscription in Subscription.api_list(customer=self.stripe_id, **kwargs):
+            Subscription.sync_from_stripe_data(stripe_subscription)
 
 
 class Event(StripeEvent):