Cannot create user with Ed25519-sk SSH key.

[Zelaf]

I tried running the script with an existing ED25519-sk key and it refused because the SSH key was Ed25519-sk.

 Does this look correct? [Y/n] y

 Creating your account...  Account creation failed: {
    "message": {
        "key": "Expected ecdsa-sha2-nistp256, ecdsa-sha2-nistp384, ecdsa-sha2-nistp521, ssh-rsa, ssh-dss, or ssh-ed25519"
    }
}
 
 If you think this is a bug, please report it to 
 -> https://github.com/hashbang/hashbang.sh/issues/
 
 The installer will not continue from here...

[RyanSquared]

Related: https://github.com/hashbang/hashbang.sh/blob/master/server.py#L37-L38

This list is incompatible with what we have in userdb and should be either updated or removed.

[RyanSquared]

We could expose SELECT enum_range(null::ssh_key_type) in postgrest api v1.