hardened ssh support

[johnko]

Waiting for upstream paramiko support for sha256 based hmac and kexgex
https://github.com/paramiko/paramiko/pull/356/files

[tomster]

not sure how strong we depend on the pinned version of paramiko ATM (@fschulze might have more details on that) but have you tried to simply update the installed version of paramiko via pip?