add some babel stuff

node_modules/is-date-object/index.js

@@ -0,0 +1,20 @@
+'use strict';
+
+var getDay = Date.prototype.getDay;
+var tryDateObject = function tryDateObject(value) {
+	try {
+		getDay.call(value);
+		return true;
+	} catch (e) {
+		return false;
+	}
+};
+
+var toStr = Object.prototype.toString;
+var dateClass = '[object Date]';
+var hasToStringTag = typeof Symbol === 'function' && typeof Symbol.toStringTag === 'symbol';
+
+module.exports = function isDateObject(value) {
+	if (typeof value !== 'object' || value === null) { return false; }
+	return hasToStringTag ? tryDateObject(value) : toStr.call(value) === dateClass;
+};