chore(package): update webpack to version 4.25.0 (#450)

package.json

@@ -95,7 +95,7 @@
     "typescript": "^2.6.1",
     "uglifyjs-webpack-plugin": "^2.0.0",
     "underscore-template-loader": "^1.0.0",
-    "webpack": "^4.18.1",
+    "webpack": "^4.25.0",
     "webpack-cli": "^3.0.8",
     "webpack-dev-server": "3.1.10",
     "webpack-merge": "^4.1.2",