Windowed KStream missing some reduce

[deoqc]

Hello and thx for the great lib.

I have a window-by-time aggregation that works w/ reduce when this only has an adder. But, I need to also have a subtracter and this fails w/:

java.lang.AbstractMethodError: jackdaw.streams.interop.reduce

I believe that the signature of the reduce for CljTimeWindowedKStream is missing for this case.

Thx

[deoqc]

Mixed GroupedKStream w/ GroupedKTable. My bad.