This PR adds a new model of ballot generator, the SlatePreference model, as well as two tests for the test suite.
The SlatePreference model uses the cohesion parameter of a voter to determine their ballot type; a coin weighted by the cohesion parameter is flipped repeatedly, determining the order of the slates on the ballot. The candidate names are then filled in in a PL style.
Added completion and distribution tests for the SP model.
This PR adds a new model of ballot generator, the SlatePreference model, as well as two tests for the test suite.
@jamesturk @drdeford @jgibson517 @jennjwang @ziglaser