Fixed criterion name with label which is displayed to the user.
TNL-768
Merge pull request #631 from edx/waheed/tnl768-fix-criterion-name

Fixed criterion name with label which is displayed to the user.
Catch and log DatabaseErrors in assessment.api.self.create_assessment.

TNL-812
Added test for DatabaseError in assessment.api.self.create_assessment.

TNL-812
Merge pull request #635 from edx/usman/tnl812-catch-db-errors-in-api

Catch and log DatabaseErrors in assessment.api.self.create_assessment.
TNL-62, TNL-72 and TNL-811