Remove old 0.6.0 published files that are now published to untp-*-instance.json and untp-*-schema.json.
Created by: absoludity
I just spent 0.5hr trying to figure out why we were still publishing 0.6.0 data even though we'd tagged and released 0.6.1. It turned out to be just the old files which remained after started publishing to the standard names.