added missing blank lines

Former-commit-id: 842c9a2adcc332506d299853608726d1a6c1db96 [formerly 7ba75a72c69eeda21e84594c88147516eaa03757]
Former-commit-id: 5b2dc677a2cf25c64d982fba34ff34739ccd69d8

drugstone/serializers.py

@@ -17,6 +17,7 @@ class PPIDatasetSerializer(serializers.ModelSerializer):
         model = models.PPIDataset
         fields = '__all__'
 
+
 class PDisDatasetSerializer(serializers.ModelSerializer):
     class Meta:
         model = models.PDisDataset