Integration tests fail if DockerDesktop is singed in

[beezerbt]

The testcontainers version is old and therefore the following issue: testcontainers/testcontainers-java#5121 breaks the tests if you are logged into the DockerDesktop/DockerHub.
Fix is to log out with the old version of the testcontainers.
Alternative is to upgrade the version to 18.3.

Also, postgres version has a vulnerability.

I also forked the branch and updated the README to give a newb a chance w.r.t. DockerDesktop and the alternative Podman, but I could not do a PR as there is no permission for it.