Release the lock.

def release(self):
        """
        Release the lock.
        """
        
        if self.is_locked_by_me():
            os.remove(self.lock_filename)
            logger.debug('The lock {} is released by me (pid: {}).'.format(self.lock_filename, self.pid))
        if self.fd:
            os.close(self.fd)
            self.fd = None