Fix lodash.isequal import (react-grid-layout#336)

This was breaking on Linux builds.

Author: jomasti

lib/utils.js

@@ -1,5 +1,5 @@
 // @flow
-import isEqual from 'lodash.isEqual';
+import isEqual from 'lodash.isequal';
 import React from 'react';
 export type LayoutItemRequired = {w: number, h: number, x: number, y: number, i: string};
 export type LayoutItem = LayoutItemRequired &