chore(deps): fix potetial security vulnerablilities issues

- chore(deps): fix potetial security vulnerablilities issues
- chore(deps): use terser-webpack-plugin instead of uglifyjs-webpack-plugin

https://github.com/webpack-contrib/uglifyjs-webpack-plugin

package.json

@@ -23,8 +23,8 @@
   },
   "homepage": "https://kimyvgy.github.io/simple-scrollspy/demo",
   "devDependencies": {
-    "uglifyjs-webpack-plugin": "^1.2.4",
+    "terser-webpack-plugin": "^2.3.1",
     "webpack": "^4.4.1",
-    "webpack-cli": "^2.0.13"
+    "webpack-cli": "^3.3.10"
   }
 }

webpack.config.js

@@ -1,17 +1,18 @@
-const {resolve} = require('path')
-const UglifyJsPlugin = require('uglifyjs-webpack-plugin')
+const { resolve } = require('path')
+const TerserPlugin = require('terser-webpack-plugin')
 
 module.exports = {
     entry: resolve(__dirname, 'src/index.js'),
+
     output: {
         path: resolve(__dirname, 'dist'),
         filename: 'simple-scrollspy.min.js',
         library: 'scrollSpy',
         libraryTarget: 'umd'
     },
-    plugins: [
-        new UglifyJsPlugin({
-            exclude: [/\.min\.js$/gi] // skip pre-minified libs
-        })
-    ]
+
+    optimization: {
+        minimize: true,
+        minimizer: [new TerserPlugin()],
+    },
 }