This uses the new zuul-registry container image to run the
intermediate registry. The same authentication data and certs
are used. The new registry also writes to the same swift container,
but uses different pseudo-directories so it won't clash with the
current registry. If there are problems, we can switch back easily.
After successful use of the new registry, we can delete the old data.
Change-Id: Ib855fb99c991411293a617b9b238d79a6bfae328
8223eadf01