Fixes several errors such as:
104) UserRegistrationsController via ajax sets user.locale from cookie on create
Failure/Error: I18n.locale = spree_current_user.andand.locale || cookies[:locale] || I18n.default_locale
I18n::InvalidLocale:
"pt" is not a valid locale
# ./app/helpers/i18n_helper.rb:14:in `set_locale'
# ./spec/controllers/user_registrations_controller_spec.rb:56:in `block (3 levels) in <top (required)>'