Conversion from spec/controller -> spec/request

The rails update breaks tests in spec/controller. The remaining tests of this type will either need to be converted to request type tests or deleted if no longer needed.

Includes:

appointments_controller_spec.rb
courses_controller_spec.rb
login_controller_spec.rb
pages_controller_spec.rb
podcasts_controller_spec.rb
sessions_controller_spec.rb
users_controller_spec.rb