Ku update method failing

[mdpiper]

The Ku model update method is failing.

A reproduce case can be found in permamodel/tests/test_Ku_method.py.

Traceback:

_______________________________________ test_update_Ku _______________________________________
Traceback (most recent call last):
  File "/Users/mpiper/projects/permamodel/permamodel/tests/test_Ku_method.py", line 33, in test_update_Ku
    m.update()
  File "/Users/mpiper/projects/permamodel/permamodel/components/Ku_method.py", line 1188, in update
    self.save_grids()
  File "/Users/mpiper/projects/permamodel/permamodel/components/perma_base.py", line 472, in save_grids
    if self.SAVE_HS_GRIDS:
AttributeError: 'Ku_method' object has no attribute 'SAVE_HS_GRIDS'. Did you mean: 'SAVE_TPS_GRIDS'?