Add fluentd and sensu to overcloud package list (master)

[halcyondude]

Per discussion with @larsks, we want to add the following packages to the overcloud package list.

• fluentd
• sensu

from the following repo:

• https://github.com/centos-opstools/centos-release-opstools/

This is to support centralized logging and the new OpsTools group

• https://wiki.centos.org/SpecialInterestGroup/OpsTools

Currently it looks like the URI's defined in the repo from discussion are not yet live...

@larsks please advise. @trown, @weshayutin FYI