Implemented 1s to 6s methods
added test class for PointCalculator, but it isn't used yet
implemented calculations for Yahtzee and Chance. Added helper methods
containsFourOfAKind and containsThreeOfAKind.
implemented threeOfAKindValue
implemented fourOfAKindValue
Implemented smallStraightValue
Implemented largeStraightValue
Implemented fullHouseValue