Simple docker-compose for multiple test databases

docker-compose.yml

version: '3'
services:
  postgres:
    image: postgres:10.1-alpine
    volumes:
      - ./data:/var/lib/postgresql/data
    ports:
      - '5432:5432'
    restart: always
  mysql:
    image: mysql:5.7.21
    environment:
      - MYSQL_ROOT_PASSWORD=test_password
    volumes:
      - ./data:/var/lib/mysql
    ports:
      - '3306:3306'
    restart: always