integrate changes from StatsModels 0.7 (upcoming release)#664

Merged

palday merged 12 commits intomainfrom dfk/statsmodels-007

Apr 10, 2023

+38-10

Commits on Jan 25, 2023

WIP statsmodels 0.7 upgrade
kleinschmidt
committed

Commits on Feb 4, 2023

sort out ranef implicit intercept
kleinschmidt
committed

Commits on Mar 5, 2023

use predictor matrix instead of model matrix (removed)
kleinschmidt
committed

Commits on Mar 14, 2023

Commits on Apr 7, 2023