specs POST #create calls UserMailer
add mailers spec
students_controller #create (user mailer)
implemented mailer to invite students to classroom
added logic for student emails that routes a new account email to new users, and a regular email to existing users added to a classroom.  Background worker running using delayed job
added in tighter validations for access to view classrooms and students
added in student must update account with name and password before joining their first classroom after account creation
UsresController#update. Redirects user to classroom after completing their singup.
add classroom_id to url
add hidden field tag for redirect when completing signup
redirect to classroom when student completes signup
studentscontroller#create
Features spec - adding students and send email
StudentsController#create
Tests that students are created in the db and added to the appropriate classroom.
Add database_cleaner gem to delete the test_db after every spec.
Problem was that when using selenium, it created a bunch of objects in the test_db that weren't getting deleted.
database_cleaner assures that the objects in the test db get wipped out after every spec.
resolve conflict when merging master into student_emails
change to initialize ActionMailer::Base.deliveries to an emtpy array

Not sure what's causing the behavior, but sometimes when we run the full test suite, the add_students feature spec fails because the deliveries is 4 instead of 2. Resetting the deliveries array to be empty makes the test consistent and gaurantees that there aren't extra things hanging around in the array.