webpack: remove eslint, added terser optimization in prod build

.eslintrc.js

@@ -1,29 +0,0 @@
-module.exports =
-  root: true,
-  parserOptions: {
-    parser: 'babel-eslint'
-  },
-  env: {
-    browser: true,
-    node: true,
-    mocha: true
-  },
-  globals: {
-    "expect": true,
-    "jQuery": false
-  },
-  extends: [
-    './web/core/.eslintrc.json',
-    'plugin:vue/recommended',
-    'plugin:vue-a11y/base',
-    'standard'
-  ],
-  plugins: [
-    'vue',
-    'vue-a11y'
-  ],
-  rules: {
-    'generator-star-spacing': 'off',
-    'no-debugger': process.env.NODE_ENV === 'production' ? 'error' : 'off'
-  }
-}