A teacher can enable guest access to a course

1. Login as a teacher, access a course and in the course settings allow guest access.
2. Login as a user who is not enrolled in the course and access the course.
3. Check that you have read-only access to the course activities.
4. Login as the teacher again and set a guest access password.
5. Login as the user again and attempt to access the course.
6. Check that you are required to supply the password in order to access the course.