Separate styles into 2 files

When I try to use vertical-timeline as a bower component it breaks my page layout. 
In style.css (style.scss) we have defined `height` for `<header>` and some styles for font. 

Of course it can be overwritten but I separate style into two files: 
timeline style (style.css) and style required for nice looking demo page (demo.css).

Standalone timeline still looks fine.
![vertical-timeline](https://cloud.githubusercontent.com/assets/1399832/4770158/9cf60b5c-5b82-11e4-802c-f0cfb016afe7.png)