Update to hacking 4.1.0
Update to hacking version 4.1.0.
# process, which may cause wedges in the gate later.
# Install bounded pep8/pyflakes first, then let flake8 install
-hacking>=4.0.0,<4.1.0 # Apache-2.0
+hacking>=4.1.0,<4.2.0 # Apache-2.0
flake8-import-order # LGPLv3
flake8-logging-format>=0.6.0 # Apache-2.0
