Fixed a ton of Python lint errors, enabled python lint checking.

BUG=

Review URL: https://webrtc-codereview.appspot.com/1166004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@3627 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/test/buildbot_tests.py b/test/buildbot_tests.py
index 65db525..9cd63c9 100755
--- a/test/buildbot_tests.py
+++ b/test/buildbot_tests.py
@@ -74,7 +74,7 @@
                     help='Lists all currently supported tests.')
   parser.add_option('-t', '--test', action='append', default=[],
                     help='Which test to run. May be specified multiple times.')
-  options, unused_args = parser.parse_args()
+  options, _ = parser.parse_args()
 
   if sys.platform.startswith('win'):
     test_dict = _WIN_TESTS