fix: upgrade classnames from 2.3.1 to 2.3.2

Snyk has created this PR to upgrade classnames from 2.3.1 to 2.3.2.

See this package in npm:
https://www.npmjs.com/package/classnames

See this project in Snyk:
https://app.snyk.io/org/jamesdbloom/project/16eaafd0-fedd-4627-8f06-e3d0bfeaba02?utm_source=github&utm_medium=referral&page=upgrade-pr

Author: snyk-bot

package-lock.json

@@ -21,7 +21,7 @@
     "sinon": "^7.1.1"
   },
   "dependencies": {
-    "classnames": "^2.3.1",
+    "classnames": "^2.3.2",
     "code-prettify": "^0.1.0",
     "humps": "^2.0.1",
     "lodash": "^4.17.21",