Clean step discontinuities

[pgbrodrick]

Add cleanup for common step discontinuities:

[fotxoa-geo]

w/ libraries:
https://github.com/fotxoa-geo/terraspec/blob/production/simulation/clean_libraries.py

example use:
scaling_factor = df.loc[:, 1000] / df.loc[:, 1002]
df.loc[:, 350:1000] = df.loc[:, 350:1000].mul(scaling_factor, axis=0)

w/asd files:
https://github.com/fotxoa-geo/terraspec/blob/production/utils/asdreader.py

example use:
res[:splice1_index + 1] *= res[splice1_index + 1] / res[splice1_index]

[pgbrodrick]

Needs testing & review from @pgbrodrick .