[PROPOSAL] Kill traffic_cop for ATS v8.0.0

[Leif Hedstrom]

Hi all,

I’d like to propose that we kill off traffic_cop for ATS v8.0.0. The consensus 
is that there are better system level tools to manage health checks out of band 
like it does. Doing this would require

        * Removing the synthetic health check thread from traffic_manager
        * Removing the backdoor in traffic_server
        * Modifying the init / systemd scripts to start traffic_manager directly


Susan has volunteered to do this work, as long as there are no strong arguments 
for keeping traffic_cop.

Thanks,

— Leif