Allow overriding Pillow image size limit

Similar to arkindex/tasks#195 (closed)

The patch was done in arkindex/tasks!390 (merged)

assigned to @mblanco

assigned to @mblanco

mentioned in merge request !584 (merged)

moved from arkindex/workers/import/s3#4 (moved)

changed milestone to %0.4.0

mentioned in merge request !584 (merged)

closed with merge request !584 (merged)