从创建Xcode项目的第一集开始，直到第八集让小蛇爬行起来。将来要增加蛇吃果果长大。

还有最后三集请看下面的链接。

金拇指课堂 Golden Thumb Classroom

Snake Game | Draw grid in Xcode

Snake Game | Print empty board

Snake Game | Print board with labels

Snake Game | Print the snake

Snake Game | Draw the snake

Snake Game | Move snake

Snake Game | Refactor snake moving functions and unit test them with XCTAssertEqual

Snake Game | Add 4 buttons to move the snake

Snake Game | Show a static fruit

Snake Game | Grows after eating fruit

Snake Game | Randomize fruit location