Swipe Feedback Animations

[kylermintah]

Description:

As a user, a large coloured circle should expand behind the card I am dragging to provide feedback on the result of the swipe.

Requirements to start:

• [x] #15

Requirements for completion:

• [x] Circle expand behind the front card with radius proportional to the magnitude of the swipe distance.
• [x] Circle changes colour based on the direction of the swipe (up blue, left red, right green)