fix test_tracer writer interface

clutchski · clutchski · commit 011a7346402b · 2016-11-02T21:45:26.000Z
diff --git a/tests/test_tracer.py b/tests/test_tracer.py
@@ -275,7 +275,7 @@ def __init__(self):
         self.spans = []
         self.services = {}
 
-    def write(self, spans, services=None):
+    def write(self, spans=None, services=None):
 
         # encode so things work.
         if spans:
