This adds a playbook to deploy newrelic monitoring of a mongodb installation.
*Sandbox URL*: TBD
*Merge deadline*: "None"
1. deploy a multi-node mongodb installation
1. configure valid newrelic vars overriding the new defaults here
1. run this playbook against the mongo node instances
1. verify that newrelic mongodb monitoring agent is set up and reporting data
to newrelic for the nodes.
See also https://github.com/edx-olive/configuration/pull/15 where this new
playbook was used for a client's gingko Open edX instance.
*Author notes and concerns*:
[ ] @itsyejd
[ ] edX reviewer[s] TBD