Register the signals.

def register_signals(self, app):
        """Register the signals."""
        before_record_index.connect(inject_provisional_community)
        if app.config['COMMUNITIES_OAI_ENABLED']:
            listen(Community, 'after_insert', create_oaipmh_set)
            listen(Community, 'after_delete', destroy_oaipmh_set)
        inclusion_request_created.connect(new_request)