chore(package): update uglifyjs-webpack-plugin to version 2.0.0 (#386)

package.json

@@ -92,7 +92,7 @@
     "tslint-loader": "^3.5.3",
     "typedoc": "^0.12.0",
     "typescript": "^2.6.1",
-    "uglifyjs-webpack-plugin": "^1.2.4",
+    "uglifyjs-webpack-plugin": "^2.0.0",
     "underscore-template-loader": "^1.0.0",
     "webpack": "^4.18.1",
     "webpack-cli": "^3.0.8",