Added the underscore node_module.

node_modules/underscore/amd/_set.js

@@ -0,0 +1,21 @@
+define(['./isNumber', './isArray', './isObject'], function (isNumber, isArray, isObject) {
+
+  function set (obj, path, value) {
+    var key = String(path[0]);
+
+    if (path.length === 1) {
+      obj[key] = value;
+      return;
+    }
+
+    if (!isArray(obj[key]) || !isObject(obj[key])) {
+      var nextKey = path[1];
+      obj[key] = isNumber(nextKey) ? [] : {};
+    }
+
+    return set(obj[key], path.slice(1), value);
+  }
+
+  return set;
+
+});