Remove 'hotstart_nudging_data.py'. Use 'hotstart_nudging_data' in schimpy instead.

-'hotstart_nudging_data' should be run as a command line function. It is part of schimpy package. Refer to https://github.com/CADWRDeltaModeling/schimpy/blob/master/schimpy/hotstart_nudging_data.py
-It may be necessary to re-install schimpy.

Author: HansKimDWR