Publish multiple tags

[Treora]

It would be great to be able to publish for multiple branches at once, to avoid double work like this:

"postpublish": "publish-to-git && publish-to-git --force --tag latest"

Note the goal of this example could also be achieved if one could publish both a tag and a branch (issue #5).

[Treora]

Note I implemented this in https://github.com/Treora/publish-to-git/tree/multitag (diff), but it would have to be rebased and revised if #9 is merged.