Update react monorepo to v16.8.6

Author: renovate-bot

package.json

@@ -35,9 +35,9 @@
     "husky": "1.3.1",
     "jest": "24.0.0",
     "prettier": "1.16.3",
-    "react": "16.7.0",
-    "react-dom": "16.7.0",
-    "react-test-renderer": "16.7.0",
+    "react": "16.8.6",
+    "react-dom": "16.8.6",
+    "react-test-renderer": "16.8.6",
     "ts-jest": "23.10.5",
     "ts-loader": "5.3.3",
     "tslint": "5.12.1",