Multiply exercise test to cover all possible combinations of boolean fields
Refactor generateExercise method to accept parameters array
Add a test for exercise update
Fix exercise save controller, did not convert is_hidden value properly
Fix admin templates to display is_hidden and is_answered properly
Disable answer buttons for an exercise without answers
Add "answers are not yet published" notice to site, too
Merge pull request #142 from ob-ivan/testBoolean

Add tests and fix admin bugs