py-paramiko: updated to 2.8.0

2.8.0 2021-10-09
[Feature] Add a prefetch keyword argument to SFTPClient.get/SFTPClient.getfo so users who need to skip SFTP prefetching are able to conditionally turn it off. Thanks to Github user @h3ll0r for the PR.
[Bug] Newer server-side key exchange algorithms not intended to use SHA1 (diffie-hellman-group14-sha256, diffie-hellman-group16-sha512) were incorrectly using SHA1 after all, due to a bug causing them to ignore the hash_algo class attribute. This has been corrected. Big thanks to @miverson for the report and to Benno Rice for the patch.
[Support] Remove leading whitespace from OpenSSH RSA test suite static key fixture, to conform better to spec. Credit: Alex Gaynor.
[Support] Add missing test suite fixtures directory to MANIFEST.in, reinstating the ability to run Paramiko窶冱 tests from an sdist tarball. Thanks to Sandro Tosi for reporting the issue and to Blazej Michalik for the PR.
[Support]: Update our CI to catch issues with sdist generation, installation and testing.
[Support]: Administrivia overhaul, including but not limited to:
Migrate CI to CircleCI
Primary dev branch is now main (renamed)
Many README edits for clarity, modernization etc; including a bunch more (and consistent) status badges & unification with main project site index
PyPI page much more fleshed out (long_description is now filled in with the README; sidebar links expanded; etc)
flake8, pytest configs split out of setup.cfg into their own files
Invoke/invocations (used by maintainers/contributors) upgraded to modern versions

(adam)