Miscellaneous deprecation warnings in rasterio, scikit-learn

[grovduck]

I'm finding a few warnings in some required packages using these versions:

pyimpute==0.1.2
scikit-learn==0.19.1
rasterio==1.0a12

https://github.com/perrygeo/pyimpute/blob/58706f44b0d29a9cfe98b97378e8cdb5490de5cd/src/pyimpute/_main.py#L8

DeprecationWarning: This module was deprecated in version 0.18 in favor of the
model_selection module into which all the refactored classes and functions are
moved. Also note that the interface of the new CV iterators are different from that of
this module. This module will be removed in 0.20.

https://github.com/perrygeo/pyimpute/blob/58706f44b0d29a9cfe98b97378e8cdb5490de5cd/src/pyimpute/_main.py#L109-L113

RasterioDeprecationWarning: 'src.affine' is deprecated.  Please switch to
'src.transform'. See https://github.com/mapbox/rasterio/issues/86 for details

https://github.com/perrygeo/pyimpute/blob/58706f44b0d29a9cfe98b97378e8cdb5490de5cd/src/pyimpute/_main.py#L161-L177

UserWarning: Found both 'affine' and 'transform' in rasterio.open() - choosing 'transform'

This last one also causes an UnboundLocalError in the finally block at line 232 because response_ds didn't get opened properly?

The first two didn't cause any issues. For the last one, I commented out the affine key in the profile dictionary and made transform equal to raster_info['affine'].