Add provideSnakeFood method to Field class

	* randomly places a square of food
	* next: the hard part, making the snake
	* also: making everything happen without refreshing the page.
Create Snake.move method for incrementing body coordinates

	*Snake class is already doing too much
	*next up: switch to MVC model to separate concerns
Create SnakeFood class, create MVC skeleton for snake
Create snake binder, model, controller, view.

	*Step 1: get body to move untill it runs into the endge of the canvas
Create SnakeModel slither method and SnakeView draw method

	* Draws snake each time it moves
	* Old position of snake remains on canvas as snake moves
	* next: change SnakeView draw method to redraw whole canvas
Separate rendering Field into class method rednerEcosystem

	*next: ecosystem should be superclass that calls methods
	that render field, food, and snake
Add Scene class to render field, food and snake each turn

	#ecosystem.render calls methods that render food,
	snake (snake eat will update food position), field
	*next: event loop setTimeInterval to render animation frame
Add interval for snake movement and rendering loop

	*Also, rename Scene and TurnController to
	GameView and GameController
	*snake now moves forward
	*next up: institute turn
Merge pull request #1 from mathildemouw/render_after_move

Render after move