Converts to XCTest.
Tweaks the test formatting by putting the assertion description on its own line. I think it's a little easier to read the description, and to see the values being compared.
Refactoring. Kind of out of place within a unit testing branch, but I just couldn't stand designing tests for badly named classes.

So this commit:
- Renames TTTMyScene to TTTTileScene and adds a stub unit testing class for it
- Renames TTTCardSpriteNode to TTTTileSprite and adds a stub unit testing class for it
- Removes TTTMeldNode, since it's unused.
- Removes the default unit testing class, since I want to separate by my classes
Adds a test to verify the important qualities of a tile sprite are initialized properly through the class method: the color, the number, and the size.
Oops, forgot one the ridiculous number of T's in this class structure ;-)
Adds the TileScene class to the unit testing target.
Exposes some methods for unit testing scenes...see the comment, this really belongs in an extension.
Adds some rudimentary tests for the TileScene, which included moving the dealHand method out of the scene and into a test.
Merge branch 'feature/unit-testing' into develop