Update react monorepo to v16.13.1

Author: renovate-bot

web/package-lock.json

@@ -12,8 +12,8 @@
     "highlight.js": "9.13.1",
     "htmlescape": "1.1.1",
     "ramda": "0.26.0",
-    "react": "16.6.0",
-    "react-dom": "16.6.0",
+    "react": "16.13.1",
+    "react-dom": "16.13.1",
     "react-hot-loader": "4.3.12",
     "react-lowlight": "2.0.0",
     "react-router": "4.3.1",