Initial working version

[miguelcnf]

I still need to update the client-java dep and add javadoc across the estate. I also want to run some more tests against a starter project I'm building. Anyway I think it's good for review.

Metrics are currently validated against a whitelist based on the metric name. I believe that, although restrictive this is the easiest way to make sure we only process metrics we understand. I'm open to suggestions for future iterations.

Next iterations will most likely include support for Datasource and Cache metrics as described in here since it seems simple straightforward.

We might want to include support for Custom metrics and Dropwizard but I don't see that as being as simple to do.

[brunopalos]

Lgtm. Some minor comments. 👍

[miguelcnf]

Thanks both, I've updated according to feedback.

Can I have your opinion on the groupId for this stuff before merging?

[brunopalos]

I like it :)

[miguelcnf]

Thanks 👍