Update ssl handling and building docker images

Update our django-sslserver version.  The new version makes it so we
don't need our hack to serve static files.  Fixed misspelling in the
fig ssl_app.

Use --no-cache when building our dev image.  I saw the same issue that
janet saw where we would get 404 errors when fetching .deb packages.
I'm pretty sure this happens because we cache the apt-get update
command.