fix: fix for tests

There seems to be a process to publish the module that renames the bundle-esm.js file to bundle.js. I don't know why we need to name the webpack generated file with the -esm suffix.

src/danfojs-browser/webpack.config.js

@@ -12,7 +12,7 @@ const createConfig = () => {
     target: "web",
     output: {
       path: path.resolve(__dirname, "lib"),
-      filename: "bundle-esm.js",
+      filename: "bundle.js",
       library: "dfd"
     },
     module: {