Over the last year the Ruby driver test runner has been improved to:

1. Configure itself completely via a URI string rather than relying on a multitude of environment variables
2. Provide user documentation for how to configure the server to run the driver test suite in the various configurations
3. Have the separate spec:prepare Rake task to set up auth in the cluster

Mongoid currently has some but not all of these improvements. Specifically, user documentation and spec:prepare Rake task are missing, and the test suite needs to be audited to determine if it can be configured completely via the URI.

This ticket is to provide the same testing documentation and support for Mongoid that we provide for the driver. Since the documentation would be largely identical to the driver, once the runner in Mongoid has all of the functionality that the driver's runner has, Mongoid can simply reference https://github.com/mongodb/mongo-ruby-driver/blob/master/spec/README.md for test running instructions.