When the ADFS certificates expire we need to do the following:

1. download the metadata xml from https://adfs.herts.ac.uk/FederationMetadata/2007-06/FederationMetadata.xml
2. go to https://pam.herts.ac.uk/simplesaml/admin/metadata-converter.php
3. log in (admin, normal server root password)
4. upload metadata xml
5. cut and paste the new metadata info into /var/simplesamlphp/metadata/saml20-idp-remote.php 
                                                    (we don't seem to use the sp-remote file).