include node_modules so release .zip is deployable

node_modules/es6-symbol/is-symbol.js

@@ -0,0 +1,9 @@
+"use strict";
+
+module.exports = function (value) {
+	if (!value) return false;
+	if (typeof value === "symbol") return true;
+	if (!value.constructor) return false;
+	if (value.constructor.name !== "Symbol") return false;
+	return value[value.constructor.toStringTag] === "Symbol";
+};