Add simple state

This PR adds :

• state.js which is a parseable record of:
  • the current players
  • the current turn
• a printTurn utility which prints the player line-up and whose turn it is

In a lot of games I've played it's easy to lose track of important game info. This isn't a rule proposal, it's just an aide. I also noticed that while coding that :

• the current turn calculation is gonna get really interesting if we add players
• we don't currently have a score kept clearly anywhere