Bock

Closed other merge request and re-opened new one with additional changes.

Get Data - 7zip modification, added Merit section back in, removed a few URLs, created 'data' and 'bin' folders if they don't already exist data_paths.json - added sections for merit and nhdplus fdr/far back in NHD_Navigate.Rmd - modified travel time calcuation to use VA_MA/EROM per-flowline velocity estimate; changed aggregation function for segments to derive multiline features with sequentially correct US-> DS node ordering.