[DRE-maint] ruby-devise-two-factor is marked for autoremoval from testing

[Debian testing autoremoval watch]

ruby-devise-two-factor 3.0.0-2 is marked for autoremoval from testing on 2017-12-26

It (build-)depends on packages with these RC bugs:
880276: ruby-encryptor: test using GCM with IV option fails after fix for CVE-2016-7798