Update webpack-subresource-integrity to fix Windows builds (#1203)

Author: gaearon

packages/react-scripts/package.json

@@ -64,7 +64,7 @@
     "webpack": "1.14.0",
     "webpack-dev-server": "1.16.2",
     "webpack-manifest-plugin": "1.1.0",
-    "webpack-subresource-integrity": "0.7.0",
+    "webpack-subresource-integrity": "0.8.1",
     "whatwg-fetch": "1.0.0"
   },
   "devDependencies": {