Fix lazyi18n in local dev with spring

Ensures that the base backend is already loaded because otherwise
things get sad sometimes

Change-Id: I37306327466d0bbdda8126d79fb96695a52675a3
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/256224
Reviewed-by: Cody Cutrer <cody@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>

spec/spec_helper.rb

@@ -853,6 +853,8 @@ RSpec.configure do |config|
   end
 end
 
+require 'lazy_presumptuous_i18n_backend'
+
 class LazyPresumptuousI18nBackend
   def stub(translations)
     @stubs = translations.with_indifferent_access