Add a "Reviewed by Hound" badge

[salbertson]

[elasticmachine]

Since this is a community submitted pull request, a Jenkins build has not been kicked off automatically. Can an Elastic organization member please verify the contents of this patch and then kick off a build manually?

[andrewvc]

This is nice to add, but I suppose this doesn't link anywhere specific to the beats project? Is there an overview page for violations across the project?

[salbertson]

@andrewvc you're right, it links to Hound's landing page. All of Hound's interaction and UI is directly in GitHub so there isn't anything beats specific to link to.

[salbertson]

@andrewvc it's simply sharing that the project uses Hound, and a bit of marketing for a free-for-open-source service. What do you think?

[salbertson]

👏