Added support for publish and track subcommands for hotfix
The trouble is, this isn't a valid completion for any released version of git-flow: https://github.com/nvie/gitflow/blob/master/git-flow-hotfix#L45-49
I'd happily merge this into the develop branch of git-flow-completion, but it shouldn't be merged into master until git-flow's develop branch is merged into master. Do you mind opening a pull request against develop?
Done: #23 :)