Remove some technical debt around the release process
As part of gitlab-com/gl-infra/delivery#474 (closed), we're going to need to add additional logic and specs to the release process in release-tools. Removing some of this technical debt will make that easier.
317fe8e5 - Remove docker_version from release specs
Last use was 2d5a52c5.
f0b3c440 - Use logger.fatal for failed CNG release
The Raven capture will happen via Sentry appender.
d36f579c - Add Fuubar
I just like it!
bac2ed76 - Remove conditional Omnibus version files
We're well past any releases that would exclude these files.
8919ab66 - Remove the need for a CNGImageRelease fixture
We never did anything with the fixture repository, just created it and then stubbed its release.
We can avoid doing this and still verify the release is executed by using a stubbed constant with a spy.