Comment 7 for bug 1705469

I'm not sure there's going to be a perfectly clean way of doing this. IF we only care about loading ascii bytestrings then we could probably force the load of the text as bytestring then yaml.load it (I don't see a way of directly yaml.loading bytestrings). Does that sound good? We could also revert both commits and just live with the bug, telling people to upgrade to ocata or above.