Increment `global_step` at end of iter?
global_step currently increments at the start of a batch: https://github.com/williamFalcon/pytorch-lightning/blob/f18aee30a530149524b7004b6215a08110dca653/pytorch_lightning/trainer/train_loop_mixin.py#L77
That means at batch_nb = 0, global_step = 1. Shouldn't global_step update at the end of the iter, so batch_nb = 0 when global_step = 0?