Remove yubikey information at the end of the README

stepup/README.md

@@ -58,20 +58,6 @@ Then, bootstrap the SRAA. For this, you will need to have a Yubikey. Replace Yub
 docker compose exec middleware  /var/www/html/bin/console middleware:bootstrap:identity-with-yubikey urn:collab:person:dev.openconext.local:admin dev.openconext.local "Your Name" Your@email nl_NL Yubikey_ID
 ```
 
-You also need a Yubikey API key for your Yubikey to work. You can get it here:
-https://upgrade.yubico.com/getapikey/
-Create the following file "stepup/gateway/surfnet_yubikey.yaml" which should contain:
-
-```
-surfnet_yubikey_api_client:
-  credentials:
-    client_id: 'YOUR_CLIENT_ID'
-    client_secret: 'YOUR_SECRET'
-```
-
-```
-
-
 Mailcatcher is included. You can view the email by going to http://localhost:1080
 
 A SimpleSAMLPHP sp is included. It can be accessed at https://ssp.dev.openconext.local/simplesaml/sp.php