Neocomplete is required for correct work

Good day, @Slava.

It looks like **tern-meteor** doesn't work correctly (as it is showed at gif demo no 1) for Vim in case either [neocomplete](https://github.com/Shougo/neocomplete.vim) or [neocomplcache](https://github.com/Shougo/neocomplcache.vim) plugin is not presented. So, why not to include their installation step in the ``README.md`` file.