Install colordiff everywhere

Summary:
To compare two states of a configuration file, or two command outputs
is a current debug activity, and diff a b gains a lot of visibility
with colordiff. As such, it makes sense to install it everywhere.

The package exists on Debian, FreeBSD, EPEL for Fedora downstreams.

Reviewers: dereckson

Reviewed By: dereckson

Differential Revision: https://devcentral.nasqueron.org/D3079