Removed source maps from the e2e tests, also updated to a parallel ve…

…rsion of uglifyJS

config-overrides.js

@@ -1,7 +1,11 @@
+const rewireUglifyjs = require('react-app-rewire-uglifyjs');
+
 module.exports = function override(config, env) {
   config.module.rules.push({
       test: /\.worker\.js$/,
       use: { loader: 'worker-loader' }
     })
+
+  config = rewireUglifyjs(config);
   return config;
 }

package.json

@@ -74,7 +74,7 @@
     "server:dev": "nodemon ./server/test-malcolm-server.js",
     "start": "npm run config:dev && concurrently \"npm run server:dev\" \"react-app-rewired start\"",
     "ui-only": "npm run config:dev && react-app-rewired start",
-    "build:e2e": "npm run config:dev && cross-env REACT_APP_E2E=true react-app-rewired build",
+    "build:e2e": "npm run config:dev && cross-env GENERATE_SOURCEMAP=false REACT_APP_E2E=true react-app-rewired build",
     "build": "react-app-rewired build && npm run config:prod",
     "test": "react-app-rewired test --env=jsdom --coverage",
     "test:watch": "react-app-rewired test --env=jsdom --watch",
@@ -118,6 +118,7 @@
     "nodemon": "^1.17.4",
     "prettier": "^1.12.1",
     "q-i": "^2.0.1",
+    "react-app-rewire-uglifyjs": "^0.1.1",
     "react-app-rewired": "^1.5.2",
     "react-test-renderer": "^16.3.2",
     "source-map-explorer": "^1.6.0",