Fix run puppet cronjob.

ansible-playbook is in /usr/local, but that's not in the cron job path.

Also, although there is an ansible log setting in ansible.cfg, the
ansible-playbook command still outputs stuff. We don't want cronspam,
so add the redirection to the log file back in.

Change-Id: Id585c11cca4cbd7e1ba26adbfbe22af650ca2b50