BUG: fix weight handling, fails in some cases, see #987
TST: add failing test, bug #1221
REF/ENH: add `_init_keys` to recreate model closes #1221 closes #1609
TST: change smoke test results negbin geometric llnull
TST: TestProbitCG.test_conf_int use relative error (intermittend test failure)
BUG: proportions_chisquare_allpairs, fix hardcode pairs closes #1493
TST: predstd move __main__ to a test module
BUG: wls_prediction_std: fix if weight is scalar
CLN: pep-8
TST: wls_prediction_std: additional tests
TST wls_prediction_std add tests for OLS and confint
REF: add _get_init_kwds  overwrite in CountModel
Merge pull request #1613 from josef-pkt/fix_proportions_allpairs_1493

BUG: Fix proportions allpairs #1493
Merge pull request #1582 from josef-pkt/fix_prediction_std

BUG: wls_prediction_std fix weight handling, see 987
Merge pull request #1610 from josef-pkt/clone_fix_llnull

BUG/ENH fix llnull, extra kwds to recreate model
BUG/REF: NegativeBinomial enable exposure/offset (use predict) closes #1611
CLN: remove TODO comment [skip-ci]
TST enable test for NegativeBinomial with exposure