I have a preprint in my profile (published in the journal "PeerJ") for which there is a new version. The old doi ends with "v1" and the new with "v2". What is the recommended way to make people aware of the new version? The doi (with our without the "v1") is already taken, or so the systems tells me, and so it seems I would need to delete the whole entry for v1 -- loosing the statistics about readership.