docs: function push (directory, uri, callback) {
    var db = nano(uri);
    loadDocument(directory, function (err, doc) {
      if (err) return callback.call(null, err);
      loadAttachments(doc, directory, function (err, doc) {
        if (err) return callback.call(null, err);
        db.get(doc._id, function (err, body) {
          if (err && err.reason !== "missing") return callback.call(null, err);
          if (body && body._rev) {
            doc._rev = body._rev;
          }
          db.insert(doc, doc._id, callback);
        });
      });
    });
  }