YubiKey Invalidation
YubiKeys are pretty cool, but some models (e.g., Nano) are easy to accidentally set off.
This plugin watches for YubiKey strings and sends them off for "validation" when it sees them, which has the effect of invalidating them.
Configuration
HUBOT_YUBIKEY_API_ID: API ID (the numeric one) from https://upgrade.yubico.com/getapikey/