Animate moves on launchpad lights

[subcontrabass]

Add flashing colors to show previous moves. This will aim to help visualize the flow of the game, and show when opponent moves more clearly.

[mrharpo]

Todo

• [x] write pathfinding function - fixed with #14
• [x] highlight path #14
• [x] animate path #16
• [x] clear animation after user pushes to_square #16