It's a good practice (I'd really say a must) to pin as much as
possible of the software versions used during test, so let's apply
that to paramiko.

According to https://pypi.org/project/paramiko/

, 2.4.2 is the latest
released version.  It's also easily obtainable on systems such as
Fedora 30.

Signed-off-by: Cleber Rosa <crosa@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190607152223.9467-3-crosa@redhat.com>
Signed-off-by: Cleber Rosa <crosa@redhat.com>