Add utility scripts

This commit adds a new utility script and makes sure that it is mounted
inside the containers.

distillery/resources/compose/barrel/.env.sample

@@ -4,6 +4,7 @@
 
 # Real path for volumes to be stored
 REAL_PATH=/var/www/example.slug
+DISTILLERY_DIR=/distillery/
 
 #######################
 ### Web Server settings

distillery/resources/compose/barrel/docker-compose.yml

@@ -25,6 +25,7 @@ services:
       - ${REAL_PATH}/.composer:/var/www/.composer
       - ${REAL_PATH}/data:/var/www/data
       - ${REAL_PATH}/authorized_keys:/var/www/.ssh/authorized_keys
+      - ${DISTILLERY_DIR}/utils:/utils:ro
 
 networks:
   default:

distillery/resources/templates/docker-env/barrel

@@ -1,4 +1,5 @@
 REAL_PATH=${REAL_PATH}
+DISTILLERY_DIR=${DISTILLERY_DIR}
 
 SLUG=${SLUG}
 VIRTUAL_HOST=${VIRTUAL_HOST}