Add a linux gpg role.

ansible/roles/gpg/files/yubikey_relearn_keys

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+#
+# GPG associates token serial numbers with keys. When switching to
+# another hardware token, run this script to associate the new token
+# with the keys.
+set -euo pipefail
+IFS=$'\n\t'
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+gpg-connect-agent "scd serialno" "learn --force" /bye