Bump to v4.7.0.

mean.js

@@ -1,10 +1,12 @@
-import sum from './sum';
+import baseMean from './_baseMean';
+import identity from './identity';
 
 /**
  * Computes the mean of the values in `array`.
  *
  * @static
  * @memberOf _
+ * @since 4.0.0
  * @category Math
  * @param {Array} array The array to iterate over.
  * @returns {number} Returns the mean.
@@ -14,7 +16,7 @@ import sum from './sum';
  * // => 5
  */
 function mean(array) {
-  return sum(array) / (array ? array.length : 0);
+  return baseMean(array, identity);
 }
 
 export default mean;