Bump to v4.13.0.

_baseFindKey.js

@@ -0,0 +1,26 @@
+define([], function() {
+
+  /**
+   * The base implementation of methods like `_.findKey` and `_.findLastKey`,
+   * without support for iteratee shorthands, which iterates over `collection`
+   * using `eachFunc`.
+   *
+   * @private
+   * @param {Array|Object} collection The collection to search.
+   * @param {Function} predicate The function invoked per iteration.
+   * @param {Function} eachFunc The function to iterate over `collection`.
+   * @returns {*} Returns the found element or its key, else `undefined`.
+   */
+  function baseFindKey(collection, predicate, eachFunc) {
+    var result;
+    eachFunc(collection, function(value, key, collection) {
+      if (predicate(value, key, collection)) {
+        result = key;
+        return false;
+      }
+    });
+    return result;
+  }
+
+  return baseFindKey;
+});