[DRE-maint] ruby-sentry-raven is marked for autoremoval from testing

[Debian testing autoremoval watch]

ruby-sentry-raven 2.7.2-2 is marked for autoremoval from testing on 2018-10-10

It is affected by these RC bugs:
908258: ruby-sentry-raven: FTBFS with ruby-rspec 3.8

It (build-)depends on packages with these RC bugs:
853256: ruby-sidekiq: Switch form twitter-bootstrap to libjs-bootstrap (v2 to v3)