fix: upgrade date-fns from 2.14.0 to 2.17.0

Snyk has created this PR to upgrade date-fns from 2.14.0 to 2.17.0.

See this package in npm:
https://www.npmjs.com/package/date-fns

See this project in Snyk:
https://app.snyk.io/org/github-newrelic/project/f888c3c2-125f-4ff7-a0c6-0181b3c27c8b?utm_source=github&utm_medium=upgrade-pr

Author: snyk-bot

package-lock.json

@@ -11,7 +11,7 @@
     "@mdx-js/react": "^1.6.19",
     "@newrelic/gatsby-theme-newrelic": "^1.16.3",
     "@splitsoftware/splitio-react": "^1.2.4",
-    "date-fns": "^2.14.0",
+    "date-fns": "^2.17.0",
     "feather-icons": "^4.28.0",
     "gatsby": "^2.24.91",
     "gatsby-image": "^2.4.5",