Future warning about `Index.__and__`

``` C:\Users\Arh\.virtualenvs\Jap-fByl1IQl\lib\site-packages\ankipandas\ankidf.py:839: FutureWarning: Index.__and__ operating as a set operation is deprecated, in the future this will be a logical operation matching Series.__and__. Use index.intersection(other) instead. inters = set(self_sf.index & other_nids) ```