Add support for auth db

[nightowlengineer]

Fixes #19

I haven't yet had the opportunity to test this with the integration suite, but plan to do so shortly. If you're able to so in the meantime then feel free!

[ctrimble]

I think we will need to inject some new tests, now that there are two ways to do authentication.

[nightowlengineer]

Sure 👍 Once I get the integration tests working on the above, I'll try and add a couple of test cases in.

[nightowlengineer]

After a lot of faffing around I can't get the tests working properly here. I'm on Windows and using Hyper-V, I was able to get Vagrant working with a slightly newer image and updated the provisioning script accordingly, but unfortunately the whole networking integration with the host is 'poor' at best - bridging my adapter to get access to the test instance completely blows the network throughput for the whole machine (50-60Mbps to 150Kbps...) which in turn makes the provisioning fail due to timeouts etc.

So unfortunately, I don't think I'm going to be able to work on the test side of this unless I can get around to moving this onto a Linux VM at some point, and realistically that is going to be at least a couple of weeks before I can get to it.

What would you like to do with this PR in the meantime? You could merge this onto a new branch on your repo, add the necessary tests, then pull it onto mainline that way?

[ctrimble]

I am sorry to hear that the tests are not working on your machine. Vagrant is really just there to provide a way to launch a known version of Mongo to test against. Perhaps that needs to change.

Here are some options:

• Vagrant is only needed for the integration tests. Use the skip property on the exec plugin to allow for testing against a local Mongo. Then just provide your own Mongo for testing.
• As you suggested, merge the branch into a new branch in this repo. I would then add the tests and work it into the main line of development. This might cause the change to stall.

[nightowlengineer]

Sounds good to me. I've just pushed some changes up for the tests to get them working in the first instance (and a bump in one of the plugins to work properly on Windows). The integration tests passed in full with these changes (bar skipping the Vagrant setup).

I'll try and get some additional tests in soon for the actual auth stuff.

[mharbeck]

Will this PR, by any chance, get merged soon?