publish-doc rsync now create parent dirs at dest

The job run on gallium which hosts doc.wikimedia.org. Just mkdir -p to
ensure the target destination is populated since rsync only create the
immediate parent.

So if we want to publish a doc to /master/php, the 'master' part is not
created by rsync.

Change-Id: I44dca0066302ee4ae372c1bee494de85345543e9