Running rubocop in the 2.1 mode
Running rubocop in the 2.1 mode

as chef 12.5.1, which we still support, is shipped with ruby 2.1

Signed-off-by: Artem Sidorenko <15a0730a27c69f62ab86f2b6c639fca202166c02@posteo.de>

dev-sec/chef-ssh-hardening,dev-sec/chef-ssh-hardening,hardening-io/chef-ssh-hardening,hardening-io/chef-ssh-hardening