fix: upgrade prop-types from 15.8.0 to 15.8.1

Snyk has created this PR to upgrade prop-types from 15.8.0 to 15.8.1.

See this package in npm:
https://www.npmjs.com/package/prop-types

See this project in Snyk:
https://app.snyk.io/org/jneal/project/62ec7a33-ef51-43af-8fad-1f4d6573b399?utm_source=github&utm_medium=referral&page=upgrade-pr

package.json

@@ -35,7 +35,7 @@
     "@material-ui/core": "^4.12.0",
     "@newrelic/nr1-community": "^1.2.0",
     "n": "^7.5.0",
-    "prop-types": "^15.8.0",
+    "prop-types": "^15.8.1",
     "react-circular-progressbar": "^2.0.4",
     "react-copy-to-clipboard": "^5.0.4",
     "react-select-search": "^0.10.2",