Updated kanboard for new env style

kanboard/.env.example

@@ -0,0 +1,2 @@
+DBPASS=<changeme>
+PORT=<changeme>

kanboard/docker-compose.yml

@@ -3,14 +3,12 @@ services:
   kanboard:
     image: kanboard/kanboard:latest
     ports:
-      - "80:80"
-      - "443:443"
+      - ${PORT}:80
     volumes:
       - kanboard_data:/var/www/app/data
       - kanboard_plugins:/var/www/app/plugins
-      - kanboard_ssl:/etc/nginx/ssl
     environment:
-      DATABASE_URL: mysql://kb:kb-secret@db/kanboard
+      DATABASE_URL: mysql://kb:${DBPASS}@db/kanboard
   db:
     image: mariadb:latest
     command: --default-authentication-plugin=mysql_native_password
@@ -18,11 +16,9 @@ services:
       MYSQL_ROOT_PASSWORD: secret
       MYSQL_DATABASE: kanboard
       MYSQL_USER: kb
-      MYSQL_PASSWORD: kb-secret
+      MYSQL_PASSWORD: ${DBPASS}
 volumes:
   kanboard_data:
     driver: local
   kanboard_plugins:
     driver: local
-  kanboard_ssl:
-    driver: local