docker compose: shorter default columns

When running docker compose in foreground mode, all output lines are
prefixed by a label for the container. Since we are using a default
columns value of 120, under compose we should default to a shorter value
to accomodate for the label.

Author: haarg

docker-compose.yml

@@ -17,6 +17,9 @@ services:
       - '/app/local'
     ports:
       - '8000:80'
+    environment:
+      # default is 120, shorten to work with compose label
+      COLUMNS: 96
     develop:
       watch:
         - path: ./cpanfile