Jaeger: Install jaeger-agent via chef

This issue is part of &210 (closed).

We have a bunch of services not yet running in kubernetes, that will need to send traces to jaeger. For this, we'll want a local jaeger agent on those hosts.

A previous implementation was done for omnibus: gitlab-org/omnibus-gitlab!4120 (closed) -- but that was not merged.

We'll want to port that over to a standalone cookbook.