In AureliaSpa, lock local copy of Webpack to 2.1.0-beta.25 (not any later 2.1.0 beta) due to fix aspnet#436

Author: SteveSandersonMS

templates/AureliaSpa/package.json

@@ -39,7 +39,7 @@
     "ts-loader": "^0.8.2",
     "typescript": "^2.0.0",
     "url-loader": "^0.5.7",
-    "webpack": "^2.1.0-beta.25",
+    "webpack": "2.1.0-beta.25",
     "webpack-hot-middleware": "^2.10.0"
   },
   "aurelia": {