build: update examples related dependencies

Author: kiaking

package.json

@@ -56,7 +56,7 @@
     "css-loader": "^2.1.0",
     "eslint": "^6.8.0",
     "eslint-plugin-vue-libs": "^4.0.0",
-    "express": "^4.14.1",
+    "express": "^4.17.1",
     "jasmine": "2.8.0",
     "jasmine-core": "2.8.0",
     "nightwatch": "^1.3.1",
@@ -72,8 +72,8 @@
     "vue-template-compiler": "^2.5.22",
     "vuepress": "^0.14.1",
     "vuepress-theme-vue": "^1.1.0",
-    "webpack": "^4.8.3",
-    "webpack-dev-middleware": "^1.10.0",
-    "webpack-hot-middleware": "^2.19.1"
+    "webpack": "^4.43.0",
+    "webpack-dev-middleware": "^3.7.2",
+    "webpack-hot-middleware": "^2.25.0"
   }
 }