GitLab

* [R-package] ensure that callbacks respect verbosity from params

* added tests on lgb.train()

* add lgb.cv() tests

* add fix for lightgbm()

* fix early stopping tests

* start reduucing duplication in tests

* more simplification

* more simplification

* reduce more code duplication

* centrallize more details

* reuse more logic across tests

* more code re-use

* started condensing lgb.cv test code

* further condense lgb.cv() tests

* re-use more code lgb.cv() tests

* more condensing