Add unit test for importing ed25519 ssh key
Add unit test for importing ed25519 ssh key

Back in change Id4a4e1ae4c0acd40c1fc32c3b82a8d8a62d4624d we bumped our
required cryptography package version to one that has support for
ed25519 ssh keys.

This adds a unit test to assert that ed25519 ssh key import works.

Related-Bug: #1555521

Change-Id: I5b37caa6d3b1b209722e9d74b127ea2f29b37563

mahak/nova,openstack/nova,openstack/nova,mahak/nova,mahak/nova,openstack/nova