Fix broken deps at install time
Fix broken deps at install time

- not sure if newer zope.interface works, but it can be installed
- wsgiref shouldn't be a dependency since we do not use it

ThiefMaster/indico,pferreir/indico,DirkHoffmann/indico,DirkHoffmann/indico,indico/indico,ThiefMaster/indico,indico/indico,pferreir/indico,pferreir/indico,DirkHoffmann/indico,DirkHoffmann/indico,ThiefMaster/indico,indico/indico,ThiefMaster/indico,indico/indico,pferreir/indico