Use six.moves.urllib.parse instead of urlparse

To keep Python 3.x compatibility, use six.moves.urllib.parse
to replace urlparse.

Add six as a dependency in test_requirements.txt

Change-Id: Ia6cd042970c2d4e5d418a39e25bab32b4d93c544

test-requirements.txt

@@ -7,6 +7,7 @@ docutils==0.9.1
 discover
 fixtures>=0.3.14
 python-subunit
+six>=1.4.1
 testrepository>=0.0.17
 testtools>=0.9.32
 sphinxcontrib-programoutput

tests/test_scheduler.py

@@ -34,11 +34,11 @@ import threading
 import time
 import urllib
 import urllib2
-import urlparse
 
 import git
 import gear
 import fixtures
+import six.moves.urllib.parse as urlparse
 import statsd
 import testtools