minor fixes

Author: iliakan

package.json

@@ -73,6 +73,7 @@
     "stylus-loader": "^3",
     "trace": "^3.1.0",
     "uglify-es": "^3",
+    "terser-webpack-plugin": "^4",
     "uglifyjs-webpack-plugin": "^1",
     "webpack": "^4.44.2",
     "yaml-loader": "^0.5.0"