Speed up random shifts in data augmentation
Speed up random shifts in data augmentation

Currently, polynomial interpolation of 3rd order is done when shifting. However, that is not needed because the images are shifted by integer values (crop_left_pixels, crop_top_pixels), and there is nothing to interpolate.
Setting ```order=0``` will speed up random shifts significantly.
DeepGnosis/keras,dolaameng/keras,nebw/keras,keras-team/keras,relh/keras,kemaswill/keras,keras-team/keras,daviddiazvico/keras,kuza55/keras