minor bug fix (#225)

- parameter (line_item_ids) needs to be a list

Author: smaeda-ks

twitter_ads/campaign.py

@@ -273,7 +273,7 @@ def targeting_criteria(self, id=None, **kwargs):
         """
         self._validate_loaded()
         if id is None:
-            return TargetingCriteria.all(self.account, self.id, **kwargs)
+            return TargetingCriteria.all(self.account, line_item_ids=[self.id], **kwargs)
         else:
             return TargetingCriteria.load(self.account, id, **kwargs)