Executes a simple external command and get its output
        The command contains no pipes. Error messages are
        redirected to the standard output by default

        :param stderr: where to put stderr
        :return: output of command

def get_simple_output(self, stderr=STDOUT):
        """Executes a simple external command and get its output
        The command contains no pipes. Error messages are
        redirected to the standard output by default

        :param stderr: where to put stderr
        :return: output of command
        """
        args = shlex.split(self.cmd)
        proc = Popen(args, stdout=PIPE, stderr=stderr)
        return proc.communicate()[0].decode("utf8")