changed docker host name to service name

.env.example

@@ -39,7 +39,7 @@ DEVICEHUB_ALLOWED_HOSTS=${DEVICEHUB_DOMAIN},${DEVICEHUB_DOMAIN}:${DEVICEHUB_PORT
 DB_NAME="devicehub"
 DB_USER="ereuse"
 DB_PASSWORD="ereuse"
-DB_HOST=localhost
+DB_HOST="devicehub-postgres"
 DB_PORT=5432
 
 ####

docker-compose.yml

@@ -25,7 +25,6 @@ services:
       - .:/opt/devicehub-django
     ports:
       - ${DEVICEHUB_PORT:-8000}:${DEVICEHUB_PORT:-8000}
-     #https://docs.docker.com/compose/how-tos/startup-order/
     depends_on:
       devicehub-postgres:
           condition: service_healthy