Work around a swift bug when downloading the akanda image from DHO.
Work around a swift bug when downloading the akanda image from DHO.

Newer versions of swift have a bug that prevent output from being
streamed to stdout (https://bugs.launchpad.net/bugs/1395922).  Work
around this by saving the LATEST pointer file in /opt/stack and reading
its contents.

gandelman-a/akanda-devstack,dreamhost/akanda-devstack,rodis/akanda-devstack