IE8 doesn't support window.getComputedStyle

Hi,

I just downloaded /\*! WOW - v1.0.1 - 2014-08-15\*/ 
and ran the demo ie8 with saucelabs and get an error with ie8. 

http://mtc2.taichungdesigner.com/WOW-master/demo.html

> ```
Message: Object doesn't support this property or method
Line: 320
Char: 9
Code: 0
URI: http://mtc2.taichungdesigner.com/WOW-master/dist/wow.js
```

Any ideas?

Thanks,

Robert