ERROR: Version in "./docker-compose.yml" is unsupported. You might be seeing this error because you're using the wrong Compose file version. Either specify a supported version ("2.0", "2.1", "3.0", "3.1", "3.2") and place your service definitions under the `services` key, or omit the `version` key and place your service definitions at the root of the file to use version 1.

version: ‘2’
services:
  web:
    build: .
    context: .
    args:
      - http_proxy
      - https_proxy
      - no_proxy
    command: bundle exec rails s -b 0.0.0.0
    volumes:
      - .:/app
    ports:
      - "3000:3000"
    depends_on:
      - db
    environment:
      - POSTGRESQL_PASSWORD=abcd12345
  db:
    image: postgres:9.6.2-alpine
    environment:
      POSTGRES_USER: postgres
      POSTGRES_DB: myappnameapp_development