Merge pull request #1321 from mechanicjay/docker-compose-fix

updating docker-compose syntax

Author: jonfroehlich

docker-compose.yml

@@ -1,5 +1,3 @@
-version: '3'
-
 services:
   db:
     image: "${POSTGRES_IMAGE:-postgres}" # Can be set in rebuildanddeploy.sh, or defaults to: https://hub.docker.com/_/postgres
@@ -32,5 +30,5 @@ services:
       - "db:database"
 volumes:
   db-data:
-    external:
-      name: "makeabilitylabcswashingtonedu_${POSTGRES_VOLUME:-postgres-data}"
+    external: true
+    name: "makeabilitylabcswashingtonedu_${POSTGRES_VOLUME:-postgres-data}"