Wrong HTML example on Tabs documentation

### Vertical Tabs
The html code example says that you should include the **vertical** class on the DIV tag. 
But to work, it needs to be on the UL tag.

[examples_tab_vertical_basic.html](https://github.com/zurb/foundation/blob/master/doc/includes/tabs/examples_tabs_vertical_basic.html#L1) has the wrong way of doing it.
 [examples_tab_vertical_basic_rendered.html](https://github.com/zurb/foundation/blob/master/doc/includes/tabs/examples_tabs_vertical_basic_rendered.html#L1) has the correct way of doing it.