Add new relic processor

- I do not really know how to unit test the code
- I have not actually tried the code with new relic yet
  - https://discuss.newrelic.com/t/how-can-i-monitor-long-running-php-scripts-properly-rabbitmq-supervisord/3039/11
  - https://docs.newrelic.com/docs/agents/php-agent/configuration/php-agent-api