see: http://spring-guides.marcuschiu.com/spring-data/postgres/spring-boot-postgres-jpa.html

Run Postgres Database Server

docker run --name postgres-server \
  -e POSTGRES_DB=testdb \
  -e POSTGRES_USER=my_user \
  -e POSTGRES_PASSWORD=my_password \
  -p 5432:5432 \
  -d postgres

Run Application