- add bits for updating apt

- add bits for updating apt
- fix spec tests to include osfamily fact
- add spec tests to verify current default behavior unimpacted.
- manage the update-stamp file in puppet via content rather than a served file.
- update custom fact to return -1 if the file doesn't exist
- add spec test for custom fact
- refactor to use a variable vs a collector/override
- document parameters a bit more verbosely
- remove empty unconstrained fact
- Add osfamily fact to backports tests to facilitate functional tests on non-debian hosts