Previous index page pair is displayed when right page is removed.

[prasadsurase]

Whenever any right-side page is deleted using the 'remove' option, the booklet displays the previous page pair. Steps to reproduce:

1. Clone the repository.
2. Open the repository/example/index.html page in browser.
3. Go to any page(say '6 Default Options')
4. execute $('#mybook').booklet('remove', 5); in browser console. Currently, right-side page being displayed: '4 jQuery Booklet' Expected: right-side page to be displayed: '7 Huzzah!'