scripts: convert random standalone programs to python3 only

Nothing imports these, so should be safe to convert.

BUG=chromium:997354
TEST=CQ passes

Change-Id: I8bce97083363d76ad5abbeb2d8539677611ad2d0
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2068027
Reviewed-by: Alex Klein <saklein@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
diff --git a/scripts/cros_fuzz_unittest.py b/scripts/cros_fuzz_unittest.py
index 8dc72ab..b7b084c 100644
--- a/scripts/cros_fuzz_unittest.py
+++ b/scripts/cros_fuzz_unittest.py
@@ -8,11 +8,16 @@
 from __future__ import print_function
 
 import os
+import sys
 
 from chromite.lib import cros_logging as logging
 from chromite.lib import cros_test_lib
 from chromite.scripts import cros_fuzz
 
+
+assert sys.version_info >= (3, 6), 'This module requires Python 3.6+'
+
+
 DEFAULT_MAX_TOTAL_TIME_OPTION = cros_fuzz.GetLibFuzzerOption(
     cros_fuzz.MAX_TOTAL_TIME_OPTION_NAME,
     cros_fuzz.MAX_TOTAL_TIME_DEFAULT_VALUE)