adds compose spec for developing with mariadb backend

bitnami/express/docker-compose-mariadb.yml

@@ -0,0 +1,19 @@
+version: '2'
+
+services:
+  mariadb:
+    image: bitnami/mariadb:latest
+    environment:
+      - MARIADB_DATABASE=my_app_development
+
+  myapp:
+    tty: true # Enables debugging capabilities when attached to this container.
+    image: bitnami/express:latest
+    environment:
+      - DATABASE_URL=mysql://root@mariadb/my_app_development
+    depends_on:
+      - mariadb
+    ports:
+      - 3000:3000
+    volumes:
+      - .:/app