Incremental on MinMaxScaler

I am trying to apply `MinMaxScaler` on streaming data using dask. It seems like Incremental only support models that compute score because I got the following error message.

```
Original error is below:
------------------------
TypeError("If no scoring is specified, the estimator passed should have a 'score' method. The estimator MinMaxScaler() does not.")
```

What's the proper way to use `MinMaxScaler` on streaming data?
My current code:
```python
from dask_ml import preprocessing, wrappers

SCALER = wrappers.Incremental(preprocessing.MinMaxScaler())
SCALER.fit(df[cols])
```

In addition, documentation in this [page](https://ml.dask.org/modules/generated/dask_ml.preprocessing.MinMaxScaler.html) is misleading. Clearly `partial_fit` is not implemented so I think it probably shouldn't be in the documentation page