replace mutiprocessing.starmap() with something else

[NiklasPhabian]

map() chunks the file_list into equal chunks at the beginning of the script.
This leads to stale workers towards the end of the run.

[michaelleerilee]

Where?

[NiklasPhabian]

https://github.com/SpatioTemporal/STAREMaster_py/blob/master/create_sidecar_files.py
in the main function