Created COMMITTERS.md file

#8 earlier pull request, addressed all comments from there. 
As things currently stand... the set of committer on the repo (other than the org owners) is just me. So that wouldn't really work. The intent is that we have more than one set of eyes. 

What if we changed this to be something like: "The pull request is collectively reviewed, gathering comments and/or +1s. Any raised comments are then addressed, and re-reviewed."