Need to change `hyf:downstreamWaterBody` to `hyf:downstreamFlowPath` in flowlines script

[dkedrowski]

The file US_NHD_Flowline_HUCxx-2ttl.py still connects flowlines using hyf:downstreamWaterBody. This should be updated to hyf:downstreamFlowPath.

Updating this in the Hydrology repo will take some time as importing flowlines can be a lengthy process. It effects HUC01, HUC05, and HUC07. Future HUCxx will use the correction.

[dkedrowski]

Script is now up-to-date

HUC01, HUC05, and HUC07 in the 7201 repository are not