def mkdir(path)
      path = @uri.merge(path).path
      res = @handler.request(:mkcol, path, nil, @headers)
      res.body
    end
def mkdir(path)
      path = @uri.merge(path).path
      res = @handler.request(:mkcol, path, nil, @headers)
      res.body
    end
Makes a new directory (collection)