Testing, 1 2 3...

I've updated our github acct. so all pull requests get cc'd to this
list.

I really like how OpenImageIO reviews commits in their public dev
forum before adding them to the repo, this will let us automate the
process similarly.

If anyone objects to this approach (as spam!) please let me know, but
if no one says otherwise we'll let the commit threads begin!

-- Jeremy

Oops. This is actually a callback on commits themselves, not pull
requests. I'll disable the callback until I get it worked out.