Inference Games: new level scheme

[cdmiller]

New Levels:

Level 1. no expert guess, you play until until game over (with enough wrong guesses the expert will still win).

Level 2. expert plays, fixed interval width for each round (same as our current level 1, interval 1, IQR: 7)

Level 3. IQR: 7, interval width varies with each round (4, 2, 1, 4, 6, 10)

Level 4: IQR varies with with each round (7, 3, 1, 7, 9, 12), fixed interval width: 1.

Level 5: change both IQR and interval each round.

Level 6: both IQR and interval size varies each round, and we don't tell you the IQR, or Guess the IQR instead of guess median?

Level 7+? Guess differences game. Guess IQR game?

[russphelan]

level 1, 2, 3, and 4 changes made in commit c32d032c42b2019d438e2a9ef8bd75c0fa666b3b.

[cdmiller]

Done previously. Not the final version of levels, but a start so we can begin testing.