Fix order and showing of events cards

Ghost User
2019-05-08T19:13:15+02:00

Previous behaviour

Steps to reproduce:

1. The cards are ordered by end date and shown for the entirety of the event

2. Thus the study trip is somewhere in the middle and still shown

New behaviour

Steps to validate that it works:

1. The cards are ordered by end date

2. Study trip should not show anymore after 24 hours