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

Author: greenkeeper[bot]

package.json

@@ -109,7 +109,7 @@
     "tslint": "^5.11.0",
     "tslint-config-prettier": "^1.14.0",
     "typescript": "^3.0.1",
-    "uglifyjs-webpack-plugin": "^1.2.7",
+    "uglifyjs-webpack-plugin": "^2.0.0",
     "webpack": "^4.16.5",
     "webpack-cli": "^3.1.0",
     "webpack-dev-server": "^3.1.5"