Define project metadata tracking and publishing schema

[danxoneil]

Researchers may be interested in our project. Let's develop a schema for the exact types of info we want to collect and publish about the system. Here's a start:

-- Number of tweets reviewed
-- Number of tweets classified (i.e. tweets that hit the Admin tool)
-- Number of tweets replied to in Admin tool
-- Number of Twitter users who clicked/ landed/ took action (related to #5)