Roulette wheel selection

Implement roulette wheel selection
https://en.wikipedia.org/wiki/Fitness_proportionate_selection

For example, if you want to have a probability distribution like this:

• 1 - 30%
• 2 - 40%
• 3 - 25%
• 4 - 5%

You will be able to easily achieve this by passing the following argument to the new component:

{1 : 0.3, 2: 0.4, 3: 0.25, 4: 0.05}

or

{1 : 0.6, 2: 0.8, 3: 0.5, 4: 0.1}