Make translation failure error out, there are at least 1 uncovered translation...

Make translation failure error out, there are at least 1 uncovered translation failures (share with lightbox)

spec/support/i18n_raise_errors.rb

+module I18n
+  def self.just_raise_that_exception(*args)
+    raise args.first
+  end
+end
+
+I18n.exception_handler = :just_raise_that_exception