Before this change there was a need to keep addhost and
bootstrap-cosmos.sh in sync regarding what version of the cosmos deb to
scp over and later run.
Now we find the latest version as decided by `sort -V` in both addhost
and bootstrap-cosmos.sh.
Solution discussed with @fredrikt.
With recent GPG versions, a TTY seems to be required to import keys.
Since importing of keys need to work when running from cron, we
pass --no-tty to those commands. This should mean that -t doesn't
have to be passed to SSH on bootstrapping for new Debian hosts
(tested on Raspbian).
Patrik Lundin
Fredrik Thulin
Leif Johansson