unittests: handle some renamed assert methods

Python 3 renamed assert{ItemsEqual,RaisesRegexp,RegexpMatches} to
assert{CountEqual,RaisesRegex,Regex}.  Add our own handlers so we
can migrate our code now.

BUG=chromium:980619
TEST=`cros lint` is unchanged

Change-Id: I21cd4ce0b8ec6757422028d0228fea9e91cb2b1c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/1829816
Reviewed-by: Chris McDonald <cjmcdonald@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
diff --git a/api/controller/binhost_unittest.py b/api/controller/binhost_unittest.py
index 75285dc..aa034d9 100644
--- a/api/controller/binhost_unittest.py
+++ b/api/controller/binhost_unittest.py
@@ -52,7 +52,7 @@
     input_proto.uri = 'gs://chromeos-prebuilt/target'
     binhost.PrepareBinhostUploads(input_proto, self.response, self.api_config)
     self.assertEqual(self.response.uploads_dir, '/build/target/packages')
-    self.assertItemsEqual(
+    self.assertCountEqual(
         [ut.path for ut in self.response.upload_targets],
         ['Packages', 'foo.tbz2', 'bar.tbz2'])
 
@@ -217,7 +217,7 @@
                                'virtual/chromium-os-printing-1-r4.tbz2',
                                'virtual/python-enum34-1.tbz2',
                                'Packages']
-    self.assertItemsEqual(
+    self.assertCountEqual(
         [ut.path for ut in self.response.upload_targets],
         expected_upload_targets)
     # All of the upload_targets should also be in the uploads_directory