Export calculateUtils (react-grid-layout#1918)

* Export calculateUtils

* PR feedback: move calculateUtils to index exports

Author: dseif

index-dev.js

@@ -1,5 +1,6 @@
 module.exports = require("./lib/ReactGridLayout").default;
 module.exports.utils = require("./lib/utils");
+module.exports.calculateUtils = require("./lib/calculateUtils");
 module.exports.Responsive = require("./lib/ResponsiveReactGridLayout").default;
 module.exports.Responsive.utils = require("./lib/responsiveUtils");
 module.exports.WidthProvider =

index.js

@@ -1,5 +1,6 @@
 module.exports = require("./build/ReactGridLayout").default;
 module.exports.utils = require("./build/utils");
+module.exports.calculateUtils = require("./build/calculateUtils");
 module.exports.Responsive =
   require("./build/ResponsiveReactGridLayout").default;
 module.exports.Responsive.utils = require("./build/responsiveUtils");