Skip validations in migration so we don't reference columns that don't exist.

Fixes #3584
Re-add test_mailer view so that TestMailer functions.  Change TestMailer to take an id, so it can support Resque/Sidekiq.  Update controller to pass an id rather than the user object itself.  Update spec to use persisted user.

Remove the 'try(:id)' and just depend on the controller itself to ensure we have a legitimate current_user

Fixes #3581
Credit Card expiry comparison logic incorrect outside of UTC - would fail with card_expired method if CC is expiring this month

Fixes #3578
capybara 2.1 requires visible: false to match elements in <head>, and other invisible elements