fix: upgrade react-helmet from 6.0.0 to 6.1.0

Snyk has created this PR to upgrade react-helmet from 6.0.0 to 6.1.0.

See this package in NPM:
https://www.npmjs.com/package/react-helmet

See this project in Snyk:
https://app.snyk.io/org/github-newrelic/project/7fcca766-b226-4202-a6f2-d2d816b1e69d?utm_source=github&utm_medium=upgrade-pr

package.json

@@ -32,7 +32,7 @@
     "prop-types": "^15.7.2",
     "react": "^16.12.0",
     "react-dom": "^16.12.0",
-    "react-helmet": "^6.0.0",
+    "react-helmet": "^6.1.0",
     "react-live": "^2.2.2",
     "react-markdown": "^4.3.1",
     "react-middle-ellipsis": "^1.1.0",