Added initial version of the Set Card model. The Set Card has following parameters: number, symbol, color, shading. The contents of the SetCard is it's string representation, but without color/background/fill attributes.
Added match for Set Card which uses power allValuesSameOrDifferent method which is the core rule for Set.
Correction to Set Card colors: removed black - we only should have 3 variations: red, green, blue - see Wikipedia. We will also use blue instead of purple.
Added Set Card Deck with 81 different cards.
Added SetGame class which creates CardMatchingGame with necessary parameters for Set Game.
Fixed files location for SetCard, SetCardDeck and MockDeck classes. They are moved to the Model subdir.
Extracted methods in the CardGameViewController to update card button with the data of the card and a method to create new game. These methods will be redefined in the SetGameViewController.
Added Set Game View & Controller. We now display the Set Game view cards, but we don't differentiate shading - so shading is not reflected in the UI - we will do it next.
Added shaded symbol method which takes the input symbol (not shaded - open) and applies shading to turn into special resulting symbol.