http://wiki.ubc.ca/Course:CPSC312-2016-Project2-Iterative-Prisoners-Dilemma
$ ghci
Prelude> :load Play
*Play> play always_cooperate
Your moves (new -> old): []
Their moves: []
Pick a move... (1 = cooperate, 0 = defect)
*Play> cpu_play always_cooperate always_defect
------------ Game Over --------------
Final score (CPU 1, CPU 2): (10,40)
* Best possible score: 40
* Worst possible score: 10
* Best possible group score: (30,30)
* Worst possible group score: (20,20)