Update dependency @types/react to v16.8.18 (#811)

Author: renovate[bot]

src/React.Sample.Mvc4/package.json

@@ -4,7 +4,7 @@
   "main": "index.js",
   "license": "MIT",
   "devDependencies": {
-    "@types/react": "16.8.17",
+    "@types/react": "16.8.18",
     "@types/react-dom": "16.8.4",
     "@types/reactstrap": "8.0.1",
     "typescript": "3.4.5"