[1471] Fix quick new user modal with CAS [master]

[orenyk]

Resolves #1471, resolves #1469

• controller takes CAS into account
• cart reserver is now set as the new user after creation

[orenyk]

Alright, should be good for review!

[esoterik]

should there be a feature test for this modal?

[orenyk]

Not sure, this uses JS so it would be tricky; at the very least I should add a controller test. Good catch!

[orenyk]

This turned out to be a lot trickier than I expected. I wanted to check both password and CAS authentication by using the ActiveModel validation on cas_login that is enabled when we use CAS. Unfortunately, RSpec loads the models only once, so if we use our EnvHelpers to wrap tests in a modified ENV, they don't affect code that runs at initialization, such as model definitions.

I was able to reload the User model using the following code:

Object.send(:remove_const, 'User')
load 'user.rb'

This kinda worked, except it then breaks Devise because Devise builds associations with models during initialization, and reloading said model breaks that association. This causes a bunch of tests to then fail when we try to authenticate. Going to have to go about things a bit more hack-ishly.

[orenyk]

@esoterik ready for re-review, thanks!

[esoterik]

this looks good