Rework Docker setup, provide for remote DB, add example JSON

docker-compose.yml

@@ -0,0 +1,21 @@
+version: '2'
+
+services:
+  postgres:
+    build:
+      context: .
+      dockerfile: Dockerfile-postgres
+    environment:
+      POSTGRES_DB: oedb
+      POSTGRES_PASSWORD:
+  backend:
+    build:
+      context: .
+      dockerfile: Dockerfile-backend
+    ports:
+      - 8080:8080
+    environment:
+      DB_HOST: postgres
+      POSTGRES_PASSWORD:
+    volumes:
+      - .:/app/