Bump to v3.10.0.

internal/arraySum.js

@@ -1,16 +1,18 @@
 /**
- * A specialized version of `_.sum` for arrays without support for iteratees.
+ * A specialized version of `_.sum` for arrays without support for callback
+ * shorthands and `this` binding..
  *
  * @private
  * @param {Array} array The array to iterate over.
+ * @param {Function} iteratee The function invoked per iteration.
  * @returns {number} Returns the sum.
  */
-function arraySum(array) {
+function arraySum(array, iteratee) {
   var length = array.length,
       result = 0;
 
   while (length--) {
-    result += +array[length] || 0;
+    result += +iteratee(array[length]) || 0;
   }
   return result;
 }