Version 7.0.0

Changes

Most of the changes in this release were to take business logic out of the models and move it to services.
Additionally we've moved services that were not shared out of this gem (most went to dor-services-app or common-accessioning).

We've also merged etd_models gem into dor-services. The Embargoable concern was still left unmerged because the Etd model does not extend from Dor::Item (as it probably should). We would like to rectify this in a future release.