Switch to ginkgomon.Runner for auctioneer

Ginkgomon runner does not panic when the process fails to start [#79030198]

Signed-off-by: Abhijit Hiremagalur <abhi@pivotal.io>
Use gunk.natsClientRunner to connect

natsClientRunner will re-attempt to connect until nats comes up

[#79030198]

Signed-off-by: Abhijit Hiremagalur <abhi@pivotal.io>