This should help improve stability overall, in exchange for slightly
older package version.
Cap all the sensu plugins to their known major version that works with
the ruby interpreter shipped with the current version of
rhel/centos/oraclelinux -- currently ruby 2.0. All sensu plugins use
semantic versioning so we're assured they don't introduce breaking
changes in the capped major version.
Change-Id: Ic5ca679c40da3e466433b0e04f762d2bbffbf156
Closes-Bug: #1774123