ENH: use hg-fingerprint to create a .hg_archival.txt file when downloading a tarball
It turns out bitbucket has this nice feature that when you download a source tarball of a tag from [here](https://bitbucket.org/pypy/pypy/downloads/?tab=tags) it will add a `.hg_archival.txt` file. [Files on heptapod](https://foss.heptapod.net/pypy/pypy/tags) do not have this. I think this is an integration with the hg [`hg-fingerprint`](https://bitbucket.org/metagriffin/hg-fingerprint/src/default/) extension.
If you get this going, please enhance it to use the *last* tag, not the *first* (chronologically), since we will first label a release with a tag like `release-pypy2.7-v7.3.0rc4` , then later with a tag like `release-pypy2.7-v7.3.0` for the same node.
issue