Enable alerts when a task succeeds.

Note: Alerts are pop-up boxes. Not sure if this is desireable, but I couldn't figure out
how to make a success message show up in the same place that error messages do.

lms/djangoapps/instructor/views/tools.py

@@ -8,6 +8,7 @@ def strip_if_string(value):
         return value.strip()
     return value
 
+
 def get_student_from_identifier(unique_student_identifier):
     """
     Gets a student object using either an email address or username.