title: how can i bulk remove expired certificates from Vault
body: <p>our vault storage keep cluttering up with massive amount of expired certificates. </p>
  
  <p>there is an option to revoke a certificate using api or a lease id, but they are still available and can be queried.</p>
  
  <p>following will only revoke a certificate,</p>
  
  <pre><code>$ curl \
      --header "X-Vault-Token: ..." \
      --request POST \
      --data @payload.json \
      http://127.0.0.1:8200/v1/pki/revoke
  </code></pre>
  
  <p>is there a way to permanently remove expired certificates?</p>