Edit docker-compose file

[moslehazizi]

For issue #111

[pawlobanano]

I'm in for the simplification.

Another known way is to put this in postgres service:

healthcheck:
      test: [ "CMD-SHELL", "pg_isready -d local_container_postgresql_database -U local_container_postgresql_database_user" ]
      interval: 5s
      timeout: 5s
      retries: 5

I don't know which is better/optimal.

[moslehazizi]

Thank you, Your way is more simple, I think it is better.