api added for leaderboard and search
remove wrongly committed in files
updating views.py, it was not the same as the latest codalab master
Added django-filter to requirements
Merge branch 'master' of https://github.com/codalab/codalab
Merging with the upstream
Merge remote-tracking branch 'upstream/master'
Merge pull request #622 from prags/master

API for accessing public competition information