* disable configure_optimizers during testing * minor changes * hvd and ddp * fix precision during testing * fix ddp * fix amp * fix cpu * update dp * simplify optimizers * add test * codefactor * ref optimizer setup * chlog * suggestions * isort * rebased with master
* ref: precision plugins 1/n * ref: precision plugins 1/n
* ref: apex plugin * ref: apex plugin * ref: apex plugin