v0.3.1

Added

• tuple reducer, that returns a tuple with values.
• ndarray reducer, that returns an array with values.

Changed

• numpy arrays of int32, uint32 and float32 are now converted to their 64-bit variants instead of tuples.
• KNNIndex interface to take columns as inputs.
• Reducers now check types of their arguments.

Fixed

• Fixed delayed reporting of output connector errors.
• Python objects are now freed more often, reducing peak memory usage.