Problem: relevant commits from a private fork need to be upstreamed

[sevein]

Artefactual maintains a private version of this repository for a client. This version includes three commits that are relevant to this project and should be integrated into the main codebase:

• 156ea274126138285c4cff95f778c36fdd84365e: Add job for removing metadata files
• de27e68b5317c98d12278b1a159cfcf46c2ca658: Fix verify AIP job for uncompressed AIPs
• 71b79df0a32ac87ec97492a8dece8ba6c625418a: Move characterization job down in the transfer chain