Make test_tmpfile() pass.  (And hence test_os.py as a whole passes.)
tmpfile() now is a binary file.
diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py
index 9673172..2ddda8a 100644
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -61,10 +61,10 @@
             return
         fp = os.tmpfile()
         fp.write("foobar")
-        fp.seek(0,0)
+        fp.seek(0)
         s = fp.read()
         fp.close()
-        self.assert_(s == "foobar")
+        self.assertEquals(s, b"foobar")
 
     def test_tmpnam(self):
         import sys