Avoiding commentout in crontab

Many of engineers comment out the lines in crontab when they doesn't use the cron temporary. I think serverspec shouldn't return success when crontab have the comment outed line. 
For example,

$ crontab -l
# 30 * * * * /usr/local/script/test.sh

describe cron do
  it { should have_entry '30 * * * * /usr/local/script/test.sh'}
end

I think the above example should return fail. I modified it in this pull request.