Rotate symbols randomly

[MacRusher]

it would be great to have the symbols randomly rotated like in the real game

Originally posted by @fabiosangregorio in #6 (comment)

[fabiosangregorio]

@MacRusher i achieved a suboptimal implementation of this in my fork. If you want, take a look and let me know if you'd like me to create a PR

[MacRusher]

Sure, please create a PR and we can discuss it.

If I remember correctly, it was tricky to rotate the images, due to the bounding boxes used for placement. But I'm sure we can think something out.