Update `vundle` to `Vundle.vim`

I accidentally deleted my `~/` directory today (yeah, I know). After re-running `laptop` and the `dotfiles`, I ran into some friction involving `vundle`.

https://github.com/gmarik/Vundle.vim/blob/8db3bcb5921103f0eb6de361c8b25cc03cb350b5/doc/vundle.txt#L372-L396

`vundle` is now `Vundle.vim`. Additionally, the `Bundle` interface is deprecated
in favor of `Plugin`.