This is a state tracker for the game of [Hanabi]. It exposes a REST API for
interacting with the state of multiple games.

# Current state
At the moment, the system can track for multiple games:

  * Cards in each player's hand
  * Cards in the deck
  * Cards successfully played
  * Cards discarded/unsuccessfully played
  * Fuse tokens
  * Information tokens

# API exposed
## `/game`
### PUT
Create a new game, returning the game ID as `{id: 3}`, for instance.

## `/game/<id>`
### GET
Download a complete dump of the specified game in its current state.

## `/game/<id>/<player>`
### GET
Download the currently-visible state of the game from the perspective of the
given player.

## `/discard/<game>/<player>`
### POST
Have the specified player make the "discard" move in the specified game.

This will regain a knowledge token, if there are any to be gained, and will
draw a new card.

Supply the data `card_index=0`, for example, where `0` is the index of the card
to be discarded. (Card order is maintained strictly, so `0` refers to the first
card from the left in one's hand.)

## `/play/<game>/<player>`
### PLAY
Have the specified player attempt to play a card in the specified game.

If the play is unsuccessful, a life will be lost.

Supply the data `card_index=0`, for example, where `0` is the index of the card
to be played. (Card order is maintained strictly, so `0` refers to the first
card from the left in one's hand.)

# Future work ideas

  * Make the data storage format version-aware.
  * Track which information has been revealed about each specific card.
  * Decide/implement a way to tell the players about moves which have been made.
  * Log the game history.

[Hanabi]: https://en.wikipedia.org/wiki/Hanabi_(card_game)