adds model field
file download works need to write permissions + tests
permissions and tests added
fixes yaml test
removes cruft
fixes tests
debugging
debugging
force string for client calls
Merge pull request #659 from codalab/feature/worksheet_interface

Feature/worksheet interface
Merge pull request #651 from codalab/feature/save-yaml-for-competition

Save yaml for competition
removes cruft, adds better debugging
Merge pull request #671 from codalab/feature/fix-prediction-step

Fixes prediction step
Merge branch 'refs/heads/upstream/master' into upstream/feature/worksheet_interface