Jinja rand filter now supports repeatable randomness

By passing in a seed, which allows for repeatable randomness
  - in conjunction with a variable that's unique per-host, this allows for repeatable 'random' values per host that, most importantly, don't change for each run of the playbook
  - ex:  ansible all -m debug -a "msg={{ 60|random(seed=inventory_hostname) }}"
  - personally, I would like to use this to repeatably splay a set of cron jobs across a cluster of hosts