Add cut as a Series method
#### Problem description

It would be to have `cut` as a series method so that we can method chain. Currently, we must use `pd.cut`, for example,

```
filled_series = df.some_series.fillna(0)
pd.cut(filled_series, 10).mean()
```

it would be nice to do,

```
df.some_series.fillna(0).cut(10).mean()
```

This would also help hugely with tab completion.

#### Expected Output

To have a tab-completed series method for `cut`.