iowa.py - Initial partition in MC

[melisandeteng]

The initial partition in MC runs is "hardcoded" as being the partition from the current enacted plan (it is shapefile dataframe dependent). The number of districts for partitioning will be computed from this initial partition.
Thus the num_district parameter in the settings.yaml file is useless.
Why is that a problem? number of districts can change in time. For example, Iowa had 5 congressional districts until 2013, but current shapefiles will indicate only 4 districts. And when computing partisan metrics with vote results prior to 2013, it would be reasonable to want to have plans with 5 districts.