Effdet wrapper

[benihime91]

Hi, regarding effdet wrapper I noticed that you are doing this coc2pascal conversion

            # coco2pascal
            boxes[:, 2] = boxes[:, 2] + boxes[:, 0]
            boxes[:, 3] = boxes[:, 3] + boxes[:, 1]

But if i am not wrong the current effdet implementation returns boxes in pascal format -->

https://github.com/rwightman/efficientdet-pytorch/blob/301487e859fa8160dd3e01b7dbc54d713b392676/effdet/anchors.py#L122