Use six.moves for itertools, urllib and intern

They're renamed in python3.

Signed-off-by: Julien Cristau <jcristau@debian.org>

britney.py

@@ -185,15 +185,15 @@ import os
 import sys
 import time
 import optparse
-import urllib
 
 import apt_pkg
 
 from collections import defaultdict
 from functools import reduce, partial
-from itertools import chain, ifilter, product
+from itertools import chain, product
 from operator import attrgetter
 
+from six.moves import filter as ifilter, intern, urllib_parse as urllib
 
 from installability.builder import InstallabilityTesterBuilder
 from excuse import Excuse

britney_util.py

@@ -24,12 +24,16 @@
 import apt_pkg
 from functools import partial
 from datetime import datetime
-from itertools import chain, ifilter, ifilterfalse, izip, repeat
+from itertools import chain, repeat
 import os
 import re
 import time
 import yaml
 
+from six.moves import (filter as ifilter,
+                       filterfalse as ifilterfalse,
+                       zip as izip)
+
 from migrationitem import MigrationItem, UnversionnedMigrationItem
 
 from consts import (VERSION, BINARIES, PROVIDES, DEPENDS, CONFLICTS,

installability/tester.py

@@ -13,7 +13,8 @@
 # GNU General Public License for more details.
 
 from functools import partial
-from itertools import ifilter, ifilterfalse
+
+from six.moves import filter as ifilter, filterfalse as ifilterfalse
 
 from britney_util import iter_except