Fix rendering and representation of errors

- Error are sent as list
- Error are None if answer is fully correct
- Error is rendered as in grade user and code questions as neat CSS divs
- Fix corresponding test cases
- Fix get_question answers in models.py

1 files changed, 1 insertions, 1 deletions

diff --git a/yaksh/cpp_code_evaluator.py b/yaksh/cpp_code_evaluator.py
index f0c2029..418c655 100644
--- a/yaksh/cpp_code_evaluator.py
+++ b/yaksh/cpp_code_evaluator.py
@@ -133,7 +133,7 @@ class CppCodeEvaluator(BaseEvaluator):
                 )
                 proc, stdout, stderr = ret
                 if proc.returncode == 0:
-                    success, err = True, "Correct answer"
+                    success, err = True, None
                     mark_fraction = float(self.weight) if self.partial_grading else 0.0
                 else:
                     err = "{0} \n {1}".format(stdout, stderr)