Lab 17: Utility
    
       - Write a program that calculates the utility of 
           a bet that paid off 22% of the time 75£.
 
       - Now replace this with user input for one percentage and
           one utility value.
 
       - Now write a system that predicts the value of a 2-armed
           bandit problem.
 
       - Build the probabilities and values in.  (Start with a constant
           value output.  E.g 10% 50£ vs. 90% 5£)
 
       - Run the system and keep track of the results.
 
       - Can your system pick the optimal move?
 
       - What happens if the values change?
 
       - If your system is trying to optimise expected value, does
           it ever pick a suboptimal outcome?