separating the nix fixture from the __init__.py file to increase readability and overview over the existing fixtures Change-Id: I7a86cb729942e83a95b9eabbb09563822f3f9e54
Fix: https://git.lix.systems/lix-project/lix/issues/559 Change-Id: I75f56c801d7f16a2e1ef8e702f16f1ef91f7b01f