docker-compose.yml: rename postgres volume db(_data,-data-postgres)
docker-compose.yml: rename postgres volume db(_data,-data-postgres)

Naming the two database volumes db-data and db_data is just mean.
I don't know how that slipped through my review.

pmattmann/ecamp3,ecamp/ecamp3,usu/ecamp3,usu/ecamp3,ecamp/ecamp3,pmattmann/ecamp3,ecamp/ecamp3,usu/ecamp3,pmattmann/ecamp3,pmattmann/ecamp3,usu/ecamp3,ecamp/ecamp3