require user type (student or teacher) for new users
remvoe duplicate test case
script to fix existing users that are following themselves (removed), non-teachers with students (made into teachers), or neither students or teachers (made into students)
remove unnecessary comment
Merge pull request #797 from code-dot-org/require-type-for-users

Require type for users
Merge pull request #798 from code-dot-org/finished

DTD