Test suite does not work if you have running containers

[chris-crone]

Tests fail with:

tests_helper.go:166: assertion failed: expression is false: len(containers) == 0

[ulyssessouza]

Remember to remove mention to this issue in https://github.com/compose-spec/compatibility-test-suite/blob/master/README.md

[chris-crone]

Is this really an issue though? If you're running conformance tests, a requirement could be that the target system is clean.

[ulyssessouza]

The thing is that maybe we can isolate that by running in a dind. WDYT @chris-crone ?