codepath HW4
- Implement scrollable tray of images
- You should be able to drag the tray up or down.
- Once the tray is revealed, you shouldn't be able to drag it any more.
- After releasing the tray, it should either move to its hidden position or its revealed position.
- Dragging an image from the tray should create a new copy of the image which can be dragged into the canvas area.
- Pinching images in the canvas area should resize them
- Optional: Allow the user to rotate the image
- Optional: Add a camera icon to the tray
- Optional: Tapping the camera icon opens the camera.
- Optional: After taking a picture, the picture is added to the view as a background view
