Make the Verify action work again.
Util tests have been moved to Pinto-Common, where the Utils module lives.
Make the Statistics work again.
Slightly simpler, when using a real Stack object.
Update to match current Pinto::Statistics API.
Return failed status when dists are missing.
Add Config attribute that points to the version file.
Add methods for getting/setting a repository version.
Those stupid select* methods have been vanquised.
Write repository version file during initialization.
Consult repository version, not schema version during migrations.
Added some convenience methods for counting objects in the repository.
Added MX::MarkAsMethods for autocleaning.
Relocated check_version() method from Repository to here.
The with_packages method didn't actually work.
Test for presence (and contents) of version file.
Added RS subclass, for common package-related queries.
Moved sanity checks outside BUILD.

This allows us to construct a Repoistory object that
may not be entirely sane.  But Pinto still expects
it to be sane before running any Action.