cfis/free-image-ruby — pull request #5 by asilano (2013-06-24 08:57:07+00:00)
Title: Fix: flip_vertical! calls FlipHorizontal

I spotted this problem while trying to flip an image about its horizontal axis. It looks like a straightforward copy-paste error means that both `flip_horizontal!` and `flip_vertical!` call through to FreeImage's `FlipHorizontal` method.

I've fixed the `flip_vertical!` case to call `FlipVertical`