'Performs pip upgrade'

def update(self):

    (_, _, exit_status) = self._run_pip(self._find_working_pip, u'install    -U    --no-cache-dir    sickrage')
    if (exit_status == 0):
        sickrage.srCore.srLogger.info(u'Updating    SiCKRAGE    from    PyPi    servers')
        if sickrage.srCore.srConfig.NOTIFY_ON_UPDATE:
            srNotifiers.notify_version_update(self.get_newest_version)
        return True
    return False
