Regenerate the yarn.lock file (#37)

This doesn't change any dependency versions required for consuming
repos, but addresses some the dependency CVEs in this repo.

(Some devDependency CVEs remain coming in through storybook versions,
but this project is not widely used at Culture Amp anymore and the
effort to upgrade to new storybook versions likely isn't worth it given
we're phasing Elm out already, and the vulnerabilities all require
running untrusted input to exploit, which isn't an issue here).

Jira card: https://cultureamp.atlassian.net/browse/FEF-956