Revert "update cron interval"

[tampakrap]

This reverts commit 7eda4b4.
The reverted commit replaced interval() with fqdn_rand(), for no clear reason.
The former function though returns a list of random numbers, so we can have
agent runs multiple times per hour. fqdn_rand returns only one number, thus
this functionality was lost.

Conflicts:
manifests/agent/cron.pp

[danieldreier]

it looks to me like the failed travis CI build is due to an unrelated issue:

/home/travis/.rvm/gems/ruby-2.1.3/gems/metadata-json-lint-0.0.5/lib/metadata-json-lint/semantic/version_range.rb:30:in `parse': undefined method `gsub' for nil:NilClass (NoMethodError)

If I understand correctly, I believe the advantage to fqdn_rand is that fqdn_rand() always returns the same number on a given host, whereas interval() will generate different results each time.

That said, scheduling multiple puppet runs per hour is a totally valid use case, and I think we should support it somehow.

[tampakrap]

In case the desicion is not to use the interval module, then it needs to be removed from metadata.json

[igalic]

iirc, that was the reasoning.

[tampakrap]

Closing in favor of #167