Allow multiple packages in NED skeleton
The NED skeleton currently assumes a single NED package in the repo. I think we should be able to deal with multiple.
The repo/package container image built is already capable of shipping multiple packages. repo/netsim is obviously just a single netsim. I think we should keep these container images; for the /package is means all packages whereas for /netsim it is just the latest netsim version in the repo, assuming that the packages are all of the same NED, just different versions. We should also create repo/package-foo-3.1, repo/package-foo-3.2 so it is possible to import individual packages if necessary. Similar for netsims, we should have /netsim-foo-3.1 and /netsim-foo-3.2, so it is possible to use a specific version.