Bump to v3.2.0.

function/throttle.js

@@ -1,5 +1,4 @@
 import debounce from './debounce';
-import isFunction from '../lang/isFunction';
 import isObject from '../lang/isObject';
 
 /** Used as the `TypeError` message for "Functions" methods. */
@@ -54,7 +53,7 @@ function throttle(func, wait, options) {
   var leading = true,
       trailing = true;
 
-  if (!isFunction(func)) {
+  if (typeof func != 'function') {
     throw new TypeError(FUNC_ERROR_TEXT);
   }
   if (options === false) {