Adds tmpreaper to jenkins slave crontab.
Adds tmpreaper to jenkins slave crontab.

Schedules tmpreaper to run daily at 1am, and delete files older than 1 days from /tmp.
Fixes bug 925774

Change-Id: Iff9383d020fa3ea0cbbe85d4ea0e5fe27ba6901e

open-switch/infra_puppet-jenkins,open-switch/infra_puppet-jenkins