rietveld.py: Change three_state_keys to emit "True" or "False" query params rather than 1/2.

tests/rietveld_test.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Unit tests for rietveld.py."""
 
 import logging
 import os
 import ssl
@@ skipping 321 matching lines @@
   def test_search_all_empty(self):
     url = (
         '/search?format=json'
         '&base=base'
         '&created_after=2010-01-02'
         '&created_before=2010-01-01'
         '&modified_after=2010-02-02'
         '&modified_before=2010-02-01'
         '&owner=owner%40example.com'
         '&reviewer=reviewer%40example.com'
-        '&closed=2'
-        '&commit=2'
-        '&private=2'
+        '&closed=True'
+        '&commit=True'
+        '&private=True'
         '&keys_only=True'
         '&with_messages=True'
         '&limit=23')
     self.requests = [
         (url, '{}'),
     ]
     results = list(self.rietveld.search(
       'owner@example.com',
       'reviewer@example.com',
       'base',
@@ skipping 127 matching lines @@
     self.mock(time, 'sleep', self.MockSleep)
     self.sleep_time = 0
     with self.assertRaises(ssl.SSLError):
       self.rietveld.post('/api/1234', [('key', 'data')])
     self.assertNotEqual(self.sleep_time, 0)
 
 if __name__ == '__main__':
   logging.basicConfig(level=[
     logging.ERROR, logging.INFO, logging.DEBUG][min(2, sys.argv.count('-v'))])
   unittest.main()