mocked S3 publications are missing a slash in what they publish

[Pomax]

Doing a test publish on localhost shows the following log:

[2015-09-25T23:28:53.958Z]  INFO: publish.webmaker.org/34260 on MozBook: Successfully uploaded /mopaxian/5index.html
[2015-09-25T23:28:53.963Z]  INFO: publish.webmaker.org/34260 on MozBook: Successfully published My Goggles Remix to localhost:8001/mopaxian/5

Which suggests there is a slash missing before the index.html part of the payload. Examining the actual file on disks confirms this, where my mox/test dir contains the following two file entries:

%5Cmopaxian%5C5index.html
%5Cmopaxian%5C5index.html.meta

Also interesting is that it looks like the platform-controlled directory separator is being used, leading to %5C on windows (the \ character), which probably needs to be rewritten to a hard coded / instead (which would end up being %2F), as this isn't so much a file as it's supposed to mock a URL on the web (not sure if this is us, or whether that's noxmox doing something interesting)