Fix error caused by access of un-enrolled user trying to attempt a assessment.
Merge branch 'development' of https://github.com/Coursemology/coursemology.org into undefined_method_levels
Add back permission check.
Merge branch 'development' of https://github.com/Coursemology/coursemology.org into undefined_method_levels
Simpler enrollment checking.
Use rubocop v0.22.0 style declaration
Merge pull request #186 from jsyeo/jsyeo-line-cop

Use rubocop v0.22.0 style declaration
Merge pull request #181 from DIdiHL/undefined_method_levels

Undefined method levels
Fix answer grading nil bug in grading controller action new
Merge pull request #189 from wangqiang1208/bugfixing/assessment-gradings

Fix answer grading nil bug in grading controller action new
Merge branch 'development' of github.com:Coursemology/coursemology.org into Deploy