Add a small sleep to let a subprocess start before terminating it.

David Bolen's buildbot isn't know for it's speed, and it seems that we
may have been trying to kill the subprocess before it was fully
initialized. I ran with this change on the bot itself and it seemed to work.
diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py
index ef85be5..d13a2eb 100644
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -679,6 +679,7 @@
         # Send a subprocess a signal (or in some cases, just an int to be
         # the return value)
         proc = subprocess.Popen(*args)
+        time.sleep(0.5)
         os.kill(proc.pid, sig)
         self.assertEqual(proc.wait(), sig)