New Relic RPM instrumentation

[fbjork]

Would be great if someone could add Qu instrumentation to the rpm_contrib gem to get valuable metrics from the Qu workers.

[jnunemaker]

For future purposes, here is how sidekiq is instrumented by new relic.

https://github.com/newrelic/rpm/blob/master/lib/new_relic/agent/instrumentation/sidekiq.rb

If we get hooks/plugins in, it should be easy to add this.