public void RollIsOutOfRange()
{
var roller = new DiceRoller();
//Test if max is less than 0.
roller.Invoking(f => f.Roll(-1)).ShouldThrow <ArgumentOutOfRangeException>();
//Test if min is less than 0.
roller.Invoking(f => f.Roll(100, -1)).ShouldThrow <ArgumentOutOfRangeException>();
//Test if max is less than min. (Default min is 1).
roller.Invoking(f => f.Roll(1, 5)).ShouldThrow <ArgumentOutOfRangeException>();
}