Credential in ci-variables

[MichaelLangbein]

• https://docs.github.com/en/actions/security-guides/encrypted-secrets
• Replace creds in docker-compose with github actions?

[MichaelLangbein]

Closing for now. Using simple .env Can be re-opened if we decide to do CI. https://github.com/riesgos/async/pull/54