Refactor SSHUtils

Refactor SSHUtils

- Add utility functions to get and put remote files
- Add JumpHostHopClient class that creates an ssh connection to a remote
  server through a jumphost. This class inherits from paramiko SSHClient
  and provides all the methods SSHClient provides
- Add get_ssh_connection utility function that creates an ssh client
  object.

Change-Id: Ic5e56f53781a861e991ae02864eb2e06dacaee1f
Signed-off-by: George Paraskevopoulos <geopar@intracom-telecom.com>