Use AR associations to write User.scores_by_team.
Use AR associations to write User.scores_by_team.

zqian/gradecraft-development,UM-USElab/gradecraft-development,mkoon/gradecraft-development,peterkshultz/gradecraft-development,UM-USElab/gradecraft-development,zqian/gradecraft-development,mkoon/gradecraft-development,peterkshultz/gradecraft-development,UM-USElab/gradecraft-development,mkoon/gradecraft-development,UM-USElab/gradecraft-development,zqian/gradecraft-development,peterkshultz/gradecraft-development