Remove takeTurn responsibility from Player

- #move returns a position
- Game is responsible for updating the board
Add 'preferred' tactic

- Prefers corners or the center
- (Pretty much) plays to a draw or wins
- Fix bug when openSlots is null (no choices available)
YAGNI Game#inspect
Refactor thisPlayer -> nextPlayer

- Move all model changes into 1 line
Add heroku_san

- Deployable to Herkou
Add rails_12factor

- for serve_static_assets
- Use NoDBStrategy for deploys
Wrap deploy strategy