pubsub crashes during docker-compose up

[itsgc]

pubsub requires a valid twitch access_token with a "channel_subscriptions" scope on startup. When ran as a docker-compose service like in https://github.com/itsgc/twitch-servitor-operations it will crash during spinup since cogitator is used to fetch that token and currently needs user interaction after the stack is fully loaded to do that.

Add an env variable to provide a starting code off-band that cogitator can use to fetch a token for pubsub before doing anything else.