fleetctl: ssh doesn't do PTY setup correctly

It would be great if I could use toolbox and have the PTY setup correctly to work.

```
$ fleetctl ssh cb toolbox
The authenticity of host '172.17.8.103:22' can't be established.
RSA key fingerprint is 0f:ce:33:a2:c7:53:6c:62:4c:85:95:3b:04:15:3e:10.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '172.17.8.103:22' (RSA) to the list of known hosts.
Pulling repository fedora







ls
core-fedora
/etc/localtime is not a symlink, not updating container timezone.



ls
```