Unregister SDC from MDM/SIO Cluster
        :param sdcObj: ScaleIO SDC object
        :return: POST request response
        :rtype: Requests POST response object

def unregisterSdc(self, sdcObj):
        """
        Unregister SDC from MDM/SIO Cluster
        :param sdcObj: ScaleIO SDC object
        :return: POST request response
        :rtype: Requests POST response object
        """
        # TODO:
        # Add code that unmap volume if mapped
        self.conn.connection._check_login()
        response = self.conn.connection._do_post("{}/{}{}/{}".format(self.conn.connection._api_url, "instances/Sdc::", sdcObj.id, 'action/removeSdc'))    
        return response