Remove unused imports in test modules.
diff --git a/Lib/test/test_traceback.py b/Lib/test/test_traceback.py
index f7e7c8d..c79961e 100644
--- a/Lib/test/test_traceback.py
+++ b/Lib/test/test_traceback.py
@@ -67,7 +67,7 @@
         self.assertTrue(err[1].find("2") == err[2].find("^"))
 
     def test_bug737473(self):
-        import sys, os, tempfile, time
+        import os, tempfile, time
 
         savedpath = sys.path[:]
         testdir = tempfile.mkdtemp()