def last_tag_commit(path = Dir.pwd)
      res = ""
      g = MiniGit.new(path)
      unless (g.capturing.tag :list => true).empty?
        # git rev-list --tags --max-count=1
        res = (g.capturing.rev_list :tags => true, :max_count => 1).chomp
      end
      res
    end
def last_tag_commit(path = Dir.pwd)
      res = ""
      g = MiniGit.new(path)
      unless (g.capturing.tag :list => true).empty?
        # git rev-list --tags --max-count=1
        res = (g.capturing.rev_list :tags => true, :max_count => 1).chomp
      end
      res
    end
list_tag
 Get the last tag commit, or nil if no tag can be found