Checks that all subscriptions are subscribed

async def _check_subscriptions(self):
        """
        Checks that all subscriptions are subscribed
        """

        subscribed, url = await self._get_subscriptions()
        expect = set(settings.FACEBOOK_SUBSCRIPTIONS)

        if (expect - subscribed) or url != self.webhook_url:
            await self._set_subscriptions(expect | subscribed)
            logger.info('Updated webhook subscriptions')
        else:
            logger.info('No need to update webhook subscriptions')