node-manta: 5.3.2 -> 5.4.1
https://github.com/TritonDataCenter/node-manta/blob/master/CHANGES.md#540
https://github.com/TritonDataCenter/node-manta/blob/master/CHANGES.md#541
* Removed vendored package-lock.json, upstream included it in their repo
* Removed update script in favor of nix-update