Arrow keys always move scrollbar

[partap]

Whenever I use up or down arrow keys to navigate within a scrollable container, it moves the scroll bar, even if that means it scrolls the focused element out of the window.

I've even tried capturing the scroll event and calling preventDefault() on it, but nothing seems to make a difference.

[partap]

Update... I found a jsbin example in #151 that doesn't display the scrolling behavior. It seems that it is using v1.1.0 of the polyfill rather than v1.2.0. I set the version to 1.1.0 in my project and now it seems to work ok too.

...so...bug, I guess?