* Remove newrelic server as it is no longer supported.

If you try to start it, it connects to Newrelic and then fails to start.

```
2018-06-19 21:31:13.253 (24656) info: cmd='connect' for 'Infrastructure' returned exception type='NewRelic::Agent::ForceDisconnectException' message='Legacy server agents are no longer supported'
2018-06-19 21:31:13.253 (24655) info: worker process exited with 1 - NOT restarting
```

* We removed the newrelic role in this PR

This may want newrelic-infrastructure, but I'll let the relevant team
decide.