Add better sourcemap support for debugging

package.json

@@ -77,6 +77,7 @@
     "rollup-plugin-commonjs": "^9.1.8",
     "rollup-plugin-json": "^3.1.0",
     "rollup-plugin-node-resolve": "^3.4.0",
+    "rollup-plugin-sourcemaps": "^0.4.2",
     "rollup-plugin-visualizer": "^0.9.2",
     "semver": "^5.5.0",
     "should": "^5.2.0",

rollup.config.js

@@ -2,6 +2,7 @@ import nodeResolve from "rollup-plugin-node-resolve";
 import commonjs from "rollup-plugin-commonjs";
 import visualizer from "rollup-plugin-visualizer";
 import json from "rollup-plugin-json";
+import sourcemaps from "rollup-plugin-sourcemaps";
 
 const banner = `/** @license ms-rest-js
  * Copyright (c) Microsoft Corporation. All rights reserved.
@@ -32,6 +33,7 @@ const nodeConfig = {
   plugins: [
     nodeResolve({ module: true }),
     commonjs(),
+    sourcemaps(),
     json(),
     visualizer({ filename: "dist/node-stats.html", sourcemap: true })
   ]
@@ -53,6 +55,7 @@ const browserConfig = {
   plugins: [
     nodeResolve({ module: true, browser: true }),
     commonjs(),
+    sourcemaps(),
     visualizer({ filename: "dist/browser-stats.html", sourcemap: true })
   ]
 };