todo for you - the rest of the helpers.

NewFileSystemPlayerStore creates a FileSystemPlayerStore initialising the store if needed.

NewLeague creates a league from JSON.

NewPlayerServer creates a PlayerServer with routing configured.

FileSystemPlayerStore stores players in the filesystem.

Player stores a name with a number of wins.

PlayerServer is a HTTP interface for player information.

PlayerStore stores score information about players.

League stores a collection of players.