Ensure on tube rack save that it does not contain a tube which is already in an other tube rack
Spec for ensuring that a tube cannot be put in another tube rack if belongs to a tube rack
Add specs
Add belongs_to_tube_rack? method
Add new exception
Raise an exception when we create or update a tube rack with a tube already in another tube rack
Revert old persistor
Add specs
Remove TubeInAnotherTubeRack definition from tube rack sequel persistor
Bump version to 2.5.8.pre
Merge pull request #58 from llh1/56269790_ensure_that_a_tube_cannot_be_implicitly_moved_in_another_rack

56269790 ensure that a tube cannot be implicitly moved in another rack