[FIX] Add vobject to requirements
[FIX] Add vobject to requirements

cateee/fosdem-volunteers,jrial/fosdem-volunteers,jrial/fosdem-volunteers,jrial/fosdem-volunteers,cateee/fosdem-volunteers,cateee/fosdem-volunteers,cateee/fosdem-volunteers,FOSDEM/volunteers,FOSDEM/volunteers,FOSDEM/volunteers,jrial/fosdem-volunteers,FOSDEM/volunteers