code: function add(data, callback) {
          var id = hat() + '.json';
          repo.contents(id).add({
              content: btoa(JSON.stringify(data)),
              branch: options.branch,
              message: '+'
          }, function(err, res) {
             callback(err, res, id);
          });
      }
docs: Add a new object to the database. If successful, the callback is called
  with (err, res) in which `res` reveals the id internally chosen
  for this new item.
  
  @param {Object} data
  @param {Function} callback called with (err, result, id)