fix: upgrade multiple dependencies with Snyk

Snyk has created this PR to upgrade:
  - react from 16.11.0 to 16.14.0.
    See this package in npm: https://www.npmjs.com/package/react
  - react-dom from 16.11.0 to 16.14.0.
    See this package in npm: https://www.npmjs.com/package/react-dom

See this project in Snyk:
https://app.snyk.io/org/jswheeler/project/6e56448f-ed45-4265-9fd0-eddb0c6ab668?utm_source=github&utm_medium=referral&page=upgrade-pr

package.json

@@ -23,8 +23,8 @@
     "lodash": "^4.17.15",
     "next": "^7.0.2",
     "prop-types": "^15.6.2",
-    "react": "^16.5.2",
-    "react-dom": "^16.5.2",
+    "react": "^16.14.0",
+    "react-dom": "^16.14.0",
     "showdown": "^1.9.0",
     "superagent": "^3.8.3",
     "topcoder-healthcheck-dropin": "^1.0.3"