docs: def update_source_list(self):
          """
          update ubuntu 16 source list
          :return: 
          """
          with cd('/etc/apt'):
              sudo('mv sources.list sources.list.bak')
              put(StringIO(bigdata_conf.ubuntu_source_list_16),
                  'sources.list', use_sudo=True)
              sudo('apt-get update -y --fix-missing')