memoize: Move to utils.

We created the utils package to house standalone pure utility
functionality. The memoize module perfectly fits the utils
description. Move it in.

BUG=None
TEST=run_tests

Change-Id: I41a4efd3f455e77492eb0a5ea2d7121fd8656afd
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/1691205
Tested-by: Alex Klein <saklein@chromium.org>
Auto-Submit: Alex Klein <saklein@chromium.org>
Reviewed-by: LaMont Jones <lamontjones@chromium.org>
Commit-Queue: Alex Klein <saklein@chromium.org>
diff --git a/scripts/gerrit.py b/scripts/gerrit.py
index 1d0565d..161c84e 100644
--- a/scripts/gerrit.py
+++ b/scripts/gerrit.py
@@ -24,9 +24,9 @@
 from chromite.lib import cros_logging as logging
 from chromite.lib import gerrit
 from chromite.lib import gob_util
-from chromite.lib import memoize
 from chromite.lib import terminal
 from chromite.lib import uri_lib
+from chromite.utils import memoize
 
 
 # Locate actions that are exposed to the user.  All functions that start