chore(package): update react to version 16.8.6

Closes #1029

Author: greenkeeper[bot]

package.json

@@ -77,7 +77,7 @@
     "prismjs": "1.16.0",
     "prop-types": "15.7.2",
     "query-string": "6.4.2",
-    "react": "16.8.4",
+    "react": "16.8.6",
     "react-dnd": "7.4.3",
     "react-dnd-html5-backend": "7.4.0",
     "react-dom": "16.8.4",