Update humans.txt

I've taken the names and roles listed in the [live blog](https://docs.google.com/document/d/1ehzUZY6I9AHLE5vxrqvmiBWm49l2mul9of95HxrrHK4/edit), and added them to humans.txt.

Trivial, but nice to have :)
Merge pull request #1 from mrchrisadams/patch-1

Update humans.txt