Log Message:
py-paramiko: update to 2.3.1

2.3.1:
[Bug] 1071: Certificate support broke the no-certificate case for Ed25519 keys \ 
(symptom is an AttributeError about public_blob.) This went uncaught due to cert \ 
autoload behavior (i.e. our test suite never actually ran the no-cert case, \ 
because the cert existed!) Both issues have been fixed. Thanks to John Hu for \ 
the report.