Cell connectivity raises an error at outlet for closely cropped catchments

[scottza]

An IndexError is raised at https://github.com/sahg/PyTOPKAPI/blob/master/pytopkapi/parameter_utils/create_file.py#L567 when the catchment outlet is on the boundary of the flow direction raster

See mailing list discussion at https://groups.google.com/forum/?fromgroups=#!topic/pytopkapi/LMWBU0u8rZg

[scottza]

Fixed in 1fb52be