Bump react from 16.3.1 to 16.12.0

Bumps [react](https://github.com/facebook/react/tree/HEAD/packages/react) from 16.3.1 to 16.12.0.
- [Release notes](https://github.com/facebook/react/releases)
- [Changelog](https://github.com/facebook/react/blob/master/CHANGELOG.md)
- [Commits](https://github.com/facebook/react/commits/v16.12.0/packages/react)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

package.json

@@ -51,7 +51,7 @@
     "mongoose": "^5.0.13",
     "nconf": "^0.10.0",
     "pico-router": "^2.1.0",
-    "react": "^16.3.1",
+    "react": "^16.12.0",
     "react-dom": "^16.3.1",
     "shortid": "^2.2.4",
     "superagent": "^3.8.2",