Merge branch 'jannson' into sunset
Merge branch 'jannson' into sunset
Improve /admin/meetup and some others
Add function modifing meetup

There is an error when modifing meetup: TypeError: can't compare
offset-naive and offset-aware datetimes
Adding function enrolling meetup

Known Issus: Can not enroll  meetup right now
Finish function enrolling meetup
Fix a small bug
Add function comment, review of meetups
fix time error