Re-render Jupyter cell for batch of images.

def render(self):
        "Re-render Jupyter cell for batch of images."
        clear_output()
        self.write_csv()
        if self.empty() and self._skipped>0:
            return display(f'No images to show :). {self._skipped} pairs were '
                    f'skipped since at least one of the images was deleted by the user.')
        elif self.empty():
            return display('No images to show :)')
        if self.batch_contains_deleted():
            self.next_batch(None)
            self._skipped += 1
        else:
            display(self.make_horizontal_box(self.get_widgets(self._duplicates)))
            display(self.make_button_widget('Next Batch', handler=self.next_batch, style="primary"))