Fix syntax error in cron_test.rb

Hi

My ruby complains about the syntax on that line, i'm unsure if this is only on my machine.

gert@lerky:chef-repo/cookbooks# knife cookbook test chef-client
checking chef-client
Running syntax check on chef-client
Validating ruby files
FATAL: Cookbook file files/default/tests/minitest/cron_test.rb has a ruby syntax error:
FATAL: /home/gert/workspace/checksec/chef-repo/.chef/../cookbooks/chef-client/files/default/tests/minitest/cron_test.rb:34: syntax error, unexpected '.', expecting kEND
FATAL:         .must_match %r{/bin/sleep \d+; ...
FATAL:          ^


Ruby version:
gert@lerky:chef-repo/cookbooks# /opt/chef/embedded/bin/ruby -v
ruby 1.9.3p286 (2012-10-12 revision 37165) [x86_64-linux]